LS Engine Asembly – from ChevyDIY

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The Ultimate Assembly Guide for LS1-LS4 Chevy Engines


When assembling an engine, a certain sequence needs to be followed. Don’t make any assumptions, as every detail must be checked.

Let’s start with your expectations, power-wise, budget-wise. You must remain realistic, as a 700-hp nitrous bullet with cast pistons and stock rods is not going to enhance your image at the race track when it comes apart in spectacular fashion.

The smart thing to do is to build an LT-based engine that is capable of driving to the track, racing for the day, and then driving home. The most popular sizes are 355 to 383 ci. For this book, we built a 355-ci engine that is almost as powerful as a 383-ci version, for a lot less money.

Prepping for Assembly

The only LT block options are whether you have two- or four-bolt main bearing caps. Otherwise, the blocks are the same. When starting to plan your project, try your best to get steel caps and straps, have the deck heights checked and corrected, and ensure the lifter bores are all measured (once in awhile you find one that is scuffed up).

The block must be cleaned before you begin. We use a method that bakes the block like cleaning an oven, and then it is shot blasted. Now it is ready to be checked for any cracks. If we are going to overbore the cylinders more than .030-inch, we sonic- check all the cylinder bores for wall thickness. The LT block easily goes .060-inch oversize for a normally aspirated application. We have built several LT-based engines at 4.100 inches (.100-inch oversize). In fact, my (Myron’s) personal 1954 Chevy Sedan Delivery is powered by a 409-ci 548-hp LT1 with a 4.100-inch bore. Something to keep in mind is that the thinner the walls are, the harder it is to keep cool.

 Line boring the mains.

To install the cam bearings, start at the rear and work forward. Make sure the oil feed holes are facing the crankshaft. All cam bearings face the crankshaft. This becomes obvious when you see the main caps with the oil feed hole facing you.

Main Bearing Caps and Straps Once the walls pass inspection, we tap the threads on all of the bolt holes in the block. Any damaged or stripped bolt holes are repaired. The block is now ready to have the main bearing caps and straps installed. You need to find the best-possible machine shop to do this work, where the technicians are familiar with the intricacies of this operation. When the angled (splayed) bolt holes are drilled, it is important that they do not go into the water jacket, which would lead to a coolant leak that would be difficult to locate. Another item that is often overlooked is the dipstick clearance near the fourth main bearing cap.

The block should now be ready to have the newly installed caps and straps align bored, leaving some material for finish align honing.


After a thorough cleaning, a Magnaflux inspection (for cracks), and a dimensional check, you have some options. If it is a very nice crankshaft, you can balance it and give it a polish on the machined surfaces. This includes de-burring and a good brushing of the oil holes. You may choose to have the crankshaft ground; if you do, be sure to specify the final journal size.

One option with factory cast or steel shafts is to have them nitride coated. This is a surface hardness treatment that helps a crankshaft last linger and survive in harsh environments. The first step is to have the shaft normalized, which makes it stable so that after grinding (when it goes to be heat treated) it needs only a minimum amount of straightening. The result is a crankshaft with a very hard surface that is scuff resistant. This is not cheap, but as a rule it is less expensive than a new aftermarket crankshaft. Of course if you are building a stroker with a new (longer stroke) crankshaft, you do not have do this.

Another option is to cryogenically treat the parts. This has been popular with top-of-the-line builders with good results. This ultra-cold treatment aligns the molecular structure in the metal, resulting in a stronger part.


 The next piece of the short-block puzzle is the pistons and wrist pin assembly. Custom pistons vary in quality. The most important dimension is the piston-to-wall clearance. The most critical surface is the bottom of the ring lands, because if the ring grooves are not ultra-smooth, combustion gases can blow under the ring and cause a large loss of power. That also means that the ring end gaps need to be set precisely.

The wrist-pin-to-piston clearance is usually set by the manufacturer, but it still needs to be checked. If it is too tight, it scuffs. If it is too loose, you hear a little noise that is a “double chuckle” under a no-load situation. For a mild street engine, something about .0005-inch is in order. A maximum effort drag racing engine commands .0009-inch clearance.

The piston rings are next. Again, all of the dimensions need to be checked. This includes groove depth and width and of course, the end gap when the bores are finished.

At this point we bore the block giving the pistons just enough clearance so that after a quick hone and run through the hot tank we can mock up the assembly. The reason for not finishing the bore at this time is to keep the piston stable in the bore, which makes an accurate deck- height check possible.

We’ve chosen to use a fullfloating-design piston pin in this engine. These require no special preparation techniques and make assembly relatively easy. If you have a press-fi t pin setup, you need to make a test pin out of aluminum to avoid ruining (and buying!) the wrong piston.

To check the deck height, put a piston and rod assembly in the four corner bores and measure the amount that needs to be cut. Today’s engine blocks are much better when it comes to the factory machine work. The target dimension is around .002 inch, end-to-end. For all cast-iron blocks with steel connecting rods, set the deck height at zero and use a .040-inch-thick head gasket. This gives a quench clearance that pro- motes a quick mixture motion, leading to a chamber that is not as octane sensitive. Also look up at the pin end to make sure that the small end of the rod has clearance in the piston. Once you’re satisfied that the reciprocating assembly has proper clearances throughout, run everything through the hot tank again.

Next, check for piston-to-valve clearance (we assume the heads are assembled and ready to go). Remove the springs from the number-1 cylinder and substitute a set of lightweight springs to make the job of checking easier. We use a set of old cam bearings that had the OD turned down so that they just slip in. Remember, we are going to go back to the hone to finish the bores and a final cleaning so we don’t want to drive in a new set of cam bearings only to take them out again.

The piston-to-valve clearance needs to be sufficient so the valves and pistons never make contact. There are several things to consider: whether you’ll be using an automatic or manual gearbox, whether the engine will be living on the street or the dragstrip, or both, etc. All of these factors have a bearing on your decisions regarding the finishing details. Let’s assume everything is average for this particular build.

The intake valve clearance is usually less than the exhaust valve clearance. The reason for this is that the piston chases the exhaust valve up the bore on the exhaust stroke. If you are at the limit of the valve- train’s ability to control the valve motion, things begin to crash. Conversely, the intake valve chases the piston down the bore, and this puts the intake components under compression. Therefore, less clearance is needed. A good number for the exhaust is .100 to .125 inch, and the intake only needs .060 to .080 inch.

At this time you should check the compression ratio to make sure that it meets your specification. You need a dab of oil on the top ring on the piston to help seal things up. We use a Katech Whistler tool to accomplish this, but you could use a CC tube to figure out the compression ratio the old- fashioned way—by measuring the volume of the bore, gasket, and cylinder head at both bottom dead center (BDC) and top dead center (TDC) and comparing them to create a ratio.

Bore Honing

 The short block is now ready for the bores to be honed to their final size. The piston-to-wall clearance that you end up with depends on the piston alloy. The block is run through

the hot tank for the final time, paying the most attention to the bores. Before using a compressed-air blowgun, wipe the block with a clean white cloth coated with a rust preventative, such as AMSOIL MP. This keeps a rust haze from forming in the bores and is also the only thing that we are going to use on the bores themselves during final assembly.

Ring Gap

Next, the ring end gap needs to be checked with a feeler gauge and corrected. This can be done with a fi le or with a specialty ring grinder. Follow the piston and ring manufacturer’s gap recommendation. With too little clearance, you take a big chance of pulling a ring land off when the engine gets up to temperature. With too much ring gap, you have excessive blow-by, oil burning, and lots of smoke out the exhaust pipe. The proper gap is critical, so take the time to ensure it’s right.

Piston Pin Locks

Begin final assembly with the installation of the piston pin locks. Once you have one set of locks in the pistons, add a drop of oil in the pin bores. Install the pin in the piston and move the pin in and out to

make sure the oil is spread evenly. Wipe a little oil in the small end of the rod. Hook the two together and install the remaining pin locks. The end play of the wrist pin needs to be near zero. Otherwise the pin can act as a battering ram and drive the locks out.


With the pistons hung on the rods and ready to install, you can prepare the block for them. Install all the galley and frost plugs. Next come the cam bearings, and then install the camshaft and make sure it turns freely.

Install a main bearing and torque the cap. Measure the vertical clearance. We like to set the clearance between .0018 and .0020 inch. This applies to most engines. Any more than this makes the rotating assembly fl ow too much oil, resulting in oil pressure problems, such as low oil pressure at a hot idle. We use the same clearance on the rod bearings. One note here is that some crank- shafts have very large radii fi lets. Be sure that the bearings do touch in this area; this means the rod bearings also.

All the piston and rod assemblies are ready to be installed. To prepare the bores, wipe each bore briskly with a clean rag soaked in some lacquer thinner until the rag comes out clean. Then coat the bores with Amsoil MP, leaving a light fi lm.

Next, put a small amount of Total-Seal (a quick-seal dry assembly lube) on your finger. This is a black powder that provides the proper lubrication during the critical break-in period. It virtually eliminates cylinder-wall burnishing and glazing. Rub the top 2 inches of the bore with your finger. If you have done a good job and the bores are clean, the surface has a greenish cast to it.

Bottom End Assembly

Once you’ve accomplished all of the prep work, you can begin the bottom end assembly process. The actual assembly process doesn’t take nearly as much time as the preparation. Knowing everything will fi t correctly and that all of the bearing clearances are correct means you can simply put the parts together. Remember to use a quality assembly lubricant on all of the bearing surfaces prior to assembly.

Once you are happy with the clearance on the main bearings, it’s time to install the crankshaft. For years we have used Amsoil synthetic gear lube as the assembly oil. We use it everywhere. You don’t need much. Our rule is that if it drips on the floor, you have used too much.

There’s no real trick here; just be careful, as you need to make sure that you have proper end play, and that the rear of the thrust face on the center main is seated against the thrust surface on the crankshaft.

You are now ready to install the piston and rod assemblies. We use very little lube because when an engine runs there is very little oil above the ring travel. In the old days, dipping the piston in a can of oil was overkill. We put just a drop of oil on the skirt of the piston and rub it around, and make no attempt to lube the rings; that job is for the Quick Seat lube powder.

Install your tapered-ring compressor over the rings, being sure to space the ring end gaps evenly. Put a spot of oil on the rod bearing and install. At this time do not torque the rod bolts, just snug them. When you have all eight pistons installed, torque the rod bolts. Once this is done, be sure to move each rod pair back and forth to make certain that the rod seats against the crank cheek. Some of today’s aftermarket crankshafts have extra-large radii fi lets, which causes an interference between the edge of the rod or main bearing and the fi let. Also many of today’s rod bearings have a top and a bottom.

It is now time to install the front cover with the Optispark along with the damper and water pump. The rear seal is next. It is important to note that some seals on the engine are installed dry and others need to be oiled. Read the instructions that come with the seals.

More often than not we fi nd there is too much oil pressure when setting up the oil pump. The old rule of having 10 pounds for each 1,000 rpm is okay up 5,000 rpm. After that, it gets to be too much. My (Myron) World Challenge competition Camaro was about 40 psi at 7,000 rpm. After two years of racing, the bearings looked like new.) The spring that comes in a standard oil pump is usually set to bypass at about 40 psi with hot oil. This should be enough. You might shim the spring with one washer.

The next thing is to set the clearance between the bottom of the pickup and the pan. This dimension should be 1/4 to 3/8 inch. As for the oil pan, we typically use a road-race style as most of our customers run F- and Y-Body cars.

Top End Assembly

Installing the heads is pretty straightforward. There are just a few things to think about. We typically use new head bolts; it is cheaper than cleaning the old ones. As for head studs we do not use them on blocks with bolt holes that go into water. They almost always weep coolant into the crankcase or dribble down the outside of the engine. We use CMD Extreme Pressure Lube Number 3 under the head of the bolt. On the threads, we use silicone sealant or a Tefl on sealant. The heads are torqued in the normal fashion in accordance with the factory circular torque pattern.

On new aluminum heads, we use a brass drift and a large hammer to give each bolt a medium rap after the initial torque. Then, we loosen each bolt and re-torque. The aluminum compresses and work-hardens. This technique allows the bolts to remain at the proper torque setting.

When installing the valvetrain, it is important to make sure that the rocker arm geometry is correct. One of the major factors that determine the correct geometry is the length of the pushrods. Pushrod length is directly affected by the length of the tappet and the installed height of the valvestem, and needs to be measured carefully prior to assembly to ensure proper length Once the geometry is set and the valves are adjusted, it is time to prime the oil pump. This needs to be done before the stock LT1 intake is installed, because there is no provision on the intake to use the traditional oil pump priming tool. Be sure to install the oil filter, plug the oil pressure port, and that the drain plug is tight with a new gasket. Put in your oil of choice. Once you have primed the pump install the oil pump drive before installing the intake.

Next, install the intake manifold. Start by doing a test fi t without any sealant. Use the gaskets that match your port size; the LT has little plastic dowels that hold the gaskets in place. There should be around .040- inch clearances under both ends of the manifold, as this allows the manifold to settle. Check for both bolt hole alignment and intake port alignment. Once you are satisfied, put a little silicone around the water ports and the bottom of the intake ports along with a bead at each end of the block. Set the intake manifold in place and just snug the bolts. We are going to come back in a few hours and finish tightening the bolts to the specified torque.

Bolt the intake manifold into place. Install the throttle body, fuel rails, and injectors as shown.

Step-1: Inspect Oil Galley Plugs

1The galley plugs here are the factory style, pressed in and then staked with a chisel. This motor is mild-performance, so factory plugs are just fine.














Step-2: Inspect Oil Galley Plugs (Continued)

2There is an important galley plug at the rear of the engine not to miss. If you do, oil squirts all over the place, requiring you to remove the head and install the plug.





Step-3: Note Drive Type

3The rear plugs are screw-in types. Notice the Allen-key- style drive.






Step-4: Choose Lube

4We swear by this type of lube for our assemblies.






Step-5: Tighten Bolts

5Use the lube on the threads and under the head of the bolts; tighten to 70 ft-lbs of torque.




Step-6: Measure Clearance

06The correct way to measure rod or main bearing clearance is to use an inside and outside micrometer. Although it’s common practice to use Plasti-gauge, we feel that the micrometer is far more accurate.







6This is a very delicate operation and requires “feel.” If you are ham-fisted, try not to do this on your own. For this build we had a clearance of .0018 inch, which is what we want for a solid build. We want it below .002 and over .0018 inch of clearance.






Step-7: Choose Break-in Lube

7It is very important that you use a break-in lube with high zinc content, so the zinc acts as a barrier between the metals.












Step-8: Lube Bearings

8A small dab of lubricant on each bearing should do the trick.




Step-9: Check Galley Plug

9This series of photos shows the hidden galley plug that is inside the marked hole. Without this, the oil travels from the oil pump directly to the bearing, essentially bypassing the oil filter. This will cost you a motor! Triple check that this plug has been installed.


















Bore Preparation


Step-1: Inspect Machine

1This scale and fixture is used for determining the big-end weight of the connecting rod.






Step-2: Use Belt Sander

2To get all the end weights of the connecting rods consistent, we use a belt sander.












Step-3: Create Balance Sheet

3All the rods are weighed to find the lightest. The other seven are then machined to make them all weigh the same. The rest of the components of the connecting rod assembly are also weighed as a unit. Notice on the balance sheet that we use two big ends as part of the calculation because there are two big ends on each crank journal along with two sets of rod bearings. For the rest of the components, we use one of each and then 5 grams for oil. Add the column and divide by 2. Each number is now half of the bob-weight.


Step-4: Disassemble Bob-weight

4Here’s how a bob-weight comes apart. Great care must be taken installing them to get them evenly spaced across each journal. (The crank is then spun to determine the crank balance throughout the RPM range.)













Step-5: Tighten or Loosen Connecting Rod Bolts

5The wrong way (top left); the “just OK” way (top right) to loosen rod bolts. This (bottom left and bottom right) is the correct way to loosen them.






Step-6: Measure Rod Bearing Clearance

6The correct way to measure rod bearing clearance is to use an inside and outside micrometer.






Step-7: Insert Ring into Bore

7Tip the ring into the bore carefully.







Step-8: Square Ring

8Use ring-squaring tool to level the ring inside the cylinder bore.






Step-9: Measure End Gap

9Use feeler gauge to measure end gap. Minimum end gap is 4.5 x bore diameter in thousands of an inch.





Step-10: Adjust End Gap

10Piston ring end gap is adjusted by grinding the ends of the ring until the proper gap is achieved. The proper way to do this is by using a piston ring grinder (shown). It can also be done by hand fi ling (which should still be done after the ring is gapped very close to the target dimension), but the grinder saves a lot of time. Remember, you can make the end gap larger, but you cannot make it smaller. It’s best to creep up on the proper dimension slowly, making regular measurements until you’re within a couple thousandths. Then, finish the work by hand to ensure a smooth surface on both sides of the gapped ring.


Step-11: Clean Inside of Bore

11Use Amsoil Metal Protector or similar product to clean the inside of the bores.









Step-12: Check Ring Seat

12You can use dry assembly lube to ensure that the rings seat properly. Doing this gets a much faster ring seal than ever before. In the old days, builders dunked the pistons in oil prior to installation. Today’s modern cylinder bores are miles ahead of previous years of engine building due to modern machining tolerances. When the lube turns green, it is done doing its job.


Crankshaft Installation


Step-1: Choose Gear Lube

1We use Amsoil gear lube to assemble the motor.








Step-2: Align Bearing Tangs

2Align the tangs of the bearings together for proper alignment. Make sure the back of the bearing is completely dry before installing.



Step-3: Prepare to Torque Bolts

3Running the bolts down saves time before torquing them.





Step-4: Torque Bolts

4Spin the crank as you torque down the main caps to check for freedom. Start torquing the caps at 45 ft-lbs and then proceed to the final torque rating of 70 ft-lbs.





Step-5: Align Crankshaft Thrust Surfaces

5Force the crankshaft forward (as shown with a screwdriver between the main cap and the crankshaft, arrow) and gently tap the rear cap to the rear. When completed, set up your dial indicator and determine crankshaft endplay. You should have approximately .003 to .005 inch. The crankshaft must turn freely with no sticking points.










Piston and Rod Assembly Installation


Step-1: Lubricate Piston

1A small dab of oil should do the trick to make sure the piston is lubricated properly while you run it home.




Step-2: Check for Interference

2Under certain circumstances, some components may have interference between the crank journal and the rod bearing (left). If this is the case in your build, you must chamfer the bearings to avoid rubbing (right).







Step-3: Install Oil Rings

3Install the oil ring in its groove. We use a method of rolling it into place rather than spreading it. This is the same for the top and bottom rings.
















Step-4: Check Skirt Diameter

4Make sure that all rings go below the surface of the piston. The skirt diameter of the piston is wider by approximately .020 inch than the top lands of the piston. It is therefore important that the rings do not protrude beyond the surface.





Step-5: Use Alignment Marks

5If the rings are marked, the marks must face upward. All ring packages come with instructions, make sure to follow the specific instructions for your set.





Step-6: Install Top and Second Ring

06Install the top and second ring by inserting the tip gently and sliding the rings around the piston. Offset the ring gaps prior to installation.





6If the ring package tension is light you may be able to push the piston in with your hands.






Step-7: Tap Ring into Place

7Stiffer- tension ring packages may need to be rammed home with the butt end of a hammer.






Step-8: Guide Connecting Rod

8Guiding the connecting rod onto the crank ensures it does not knick the crank journal. There is a tool for this, but after forty years I use my fingers.





Step-9: Check Clearance Between Piston and Connecting Rod Small End

9Make sure that you have enough clearance between the two when installing your pistons. We have seen instances where custom rods, custom pistons, and custom crank shafts incur binding issues that can lead to catastrophic failure of the motor.










Step-10: Install Camshaft

10Installing the camshaft requires a steady hand, as not to damage or mar the soft cam bearing surfaces.




Step-11: Install Water Pump Drive

11Gently tap the water pump drive into place, being careful not to hit the sprockets, as they could gall.






Step-12: Add Loctite to Threads

12A dab of Red Loctite on the threads is plenty to keep the retaining bolts in place.






Step-13: Spin Bearing

13Spin the bearing to make sure it is free and does not hang up.






Step-14: Add Loctite to Cam Retainers

14Another dab of Loctite goes on the cam retainers.






Step-15: Install Camshaft Thrust Plate

15Cam retainer and fasteners are installed using loctite.





Timing Chain and Cover, Optispark and Rear Seal Installation


Step-1: Align Cam Gear Dot

1When installing the Cloyes timing set, make sure to align the cam gear dot with the crank gear’s round marking, which can be difficult to see. This is for the factory-specified timing. To advance the timing, use the triangle marking and the square marking to retard the timing, per the instructions.



Step-2: Install Crank Gear

2Use solid blows to install the crank gear; this may take a few jolts to get it seated properly.





Step-3: Install Cam Gear

3Set the motor to TDC and install the cam gear with the chain. Again, Loctite is your friend with the retaining bolts.







Step-4: Tighten Camshaft Retaining Bolts

4Tighten camshaft retaining bolts to 30 ft-lbs.







Step-5: Install Reluctor Wheel

5Install the reluctor wheel, keyed properly.







Step-6: Apply Lube to Seals

6Prior to installing the seals, it is always a good idea to apply a thin coat of lubricant such as grease on the sealing lip and shaft per the instructions from Fel-Pro. Press these seals in with a large socket or a fl at plate and a hammer. In this case, we use a press, which is ultimately the correct way. Be sure to put solid support under the cover to ensure that you do not scratch or mar the polished cover.


Step-7: Apply RTV to Cover Gasket

7Apply a thin layer of RTV to hold the cover gasket in place.






Step-8: Apply RTV to Cover

8Repeat the process on the cover.







Step-9: Tap on Timing Cover

9The timing cover may require some persuasion from a rubber mallet or, in our case, the plastic butt end of a hammer.






Step-10: Choose Timing Cover Bolts

10There are two lengths of bolts for the timing cover; finding the correct ones should be fairly straight- forward.






Step-11: Install Distributor Shaft Seal

011The distributor shaft seal is a PTFE seal and must be installed dry. Do not lubricate the lip or the seal. Put this seal in when the cover is installed on the motor. Caution: The seal tends to fold over itself and cause a lot of headaches for owners when the seal leaks.





11The best way to ensure that the seal does not leak is to work inward toward the gear prior to installation so that it does not hang up. We use a spare gear set to massage it into shape. You are not able to see if it is hung up until you start the motor.




Step-12: Verify Crank Timing

12We cut a keyway into the crank hub to verify that the crank is properly timed and to verify the accuracy of the timing. You may need to have a machine shop complete this task for you.





Step-13: Align Distributor to Camshaft

13Ultimately, it may be easier to remove the cover of the distributor to align it to the camshaft. The size for this is an E4 Torx bit.




Step-14: Install Hub

14Pound the hub into place until it seats flush against the timing gear.






Step-15: Add Lube to Rear Seal

15The rear seal gets a small amount of assembly lube to help drive it home and seal it well.




Step-16: Find Gasket Stud

16The rear main seal adapter gasket on the driver’s side should have a stud. The passenger side has an indexing dowel.





Step-17: Install Rear Main Seal

17Installing the rear main seal requires care so as to not let the seal fold upon itself. Do not use a screwdriver to do this; use your finger to massage it onto the crank, working it back and forth until it seats.




Oil System and Pan Installation


Step-1: Inspect Valley Pan Spider Spring

1Here, the valley pan spider spring is resting in position.








Step-2: Install Oil Pump Pickup

2Installing the oil pump pick up often requires a special tool and often requires welding to keep it in place.





Step-3: Test Fit Oil Pan

3Using a piece of clay and some plastic, we place the oil pan over the pump to get a satisfactory distance between the pump and pan. The ideal depth is 3/8 inch.



Step-4: Pre-Lube Oil Pump

4Pre-lubing the oil pump helps it prime faster. You must prime the pump before you start the engine for the first time.





Step-5: Add RTV to Oil Pan Gasket

5A good bead of RTV on both sides of the Fel-Pro one-piece oil pan gasket is needed.














Step-6: Install Oil Pan

6The bottom is capped off by the oil pan. (In this photo you can see that the cylinder heads are already in place. You can install the oil pan before you install the heads.)







Step-7: Add Oil Pan Straps

7Straps are added to make sure the oil pan has been evenly snugged into place. They should be tightened until compression is made on the gasket. We let the RTV set for 24 hours and then come back to retighten the bolts.






Head Installation


Step-1: Choose Gaskets

1We are using Victor Reinz gaskets (PN 5898). We did not deck this block, resulting in a .030-inch deck height. To compensate we use a .030-inch-thick head gasket, which gives a quench clearance of .060 inch, which is .020 inch more than what is considered ideal.




Step-2: Add Thread Sealer

2A small dab of Tefl on thread sealer on each thread helps seal the holes from water.






Step-3: Tighten Head Bolts

03Head bolts are tightened in three equal steps to 70 ft-lbs with a dose of fastener assembly lube. In the approved sequence, bolts are tightened in a circular pattern. The first lap starts at 30 ft-lbs, the second lap at 50 ft-lbs, and the third onto 70 ft-lbs. A smooth, careful motion with a quality torque wrench is your best bet.



3A couple firm taps on each head bolt and then another round of tightening to 70 ft-lbs saves you a lot of work later when retorquing the heads. This works best on new heads and less so on older used heads. This may seem a little crude, but it is quite effective and saves a retorque later.


Valvetrain Installation


Step-1: Add Lube to Lifters

1With a liberal amount of zinc-laden assembly lube, the lifters come next.








Step-2: Inspect Tie Bars

2These tie bars have the fl at end matching the fl at end of the lifter. Tie bars are essential and must not be omitted.







Step-3: Add Lube to Pushrods

3Zinc assembly lube is dripped on all the top and bottom of all pushrods.







Step-4: Add Oil to Valve

4A dab of oil on each valve does the trick.







Step-5: Tighten Spider Gear

5Tighten the spider gear, holding the lifter retainers in place.






Rocker Arm Installation


Step-1: Torque Rocker Studs

1Rocker studs come next and are torqued down to 55 ft-lbs.





Step-2: Install Exhaust Rocker Arm

2When the exhaust valve just barely begins to open, take the intake and run the nut down to zero lash (21198). Then roll the motor over until the intake just closes. Install the exhaust rocker arm and take it down to zero lash (21199). This procedure is used throughout the entire drivetrain. At this point you should be using this time to spin the crank shaft to notice any binds throughout the motor, i.e., camshaft ticks, connecting rod clearance, etc.















Step-3: Adjust Rocker Stud Alignment

003A quick check before you throw the valve covers on. You can use a fl at bar to see if the rocker studs are fairly equal. They should be within one turn of each other.





03One full turn of each rocker stud suffices. This is a quick way to make sure the rockers are properly snug and do not need to be fiddled with later.







3Finally, snug the lock nut tight, back off the stud nut about a 1/16 turn, then tighten both stud and lock nut as one.







Final Top End Assembly


Step-1: Prime Oil Pump

1Using a drill, the pump is primed prior to installing the gear drive to make sure the pump is functional and to pre-lube it prior to the first start up. This requires a special tool; or a modified distributor works just as well.






Step-2: Inspect Oil Pump Drive Gear

2A new gear is cheap insurance. Our old one (left) has seen a lot of use and is worn down and needed to be replaced.






Step-3: Install Oil Pump Drive Gear

3Install the oil pump drive gear.








Intake Manifold Installation


Step-1: Inspect Gaskets

1Make sure your gaskets are LT-specific with no coolant holes.



Step-2: Check Gasket Fit

2Inspect throttle body gasket for alignment and fi t.




Written by Eric McClellan and Posted with Permission of CarTechBooks