CHEVY LS1 related info


Staff member ... index.html ... eset=false

LSNext Blocks have arrived @ SDPC!!!

GOT AN LS engine swap? ... bedded#t=1 ... der-blocks ... erformance ... eo-760-hp/






ls1block5.jpg ... -lsxr.html ... sults.html ... s_engines/ ... gine_swap/

a few tips on installing a manual trans behind an LS series engine in an older muscle car, and identifying that LS engine ... r_ls_swap/ ... 8_engines/ ... _a_427_ls/

Front oxygen sensor for 2002 6L applications: 12565397

Brake booster intake manifold fitting (needed if you got your 6L engine from a truck with hydroboost, and you have a vacuum booster): 12555831

3-wire coolant temperature sensor connector: 12102748

If you want to maintain the integrity of the EVAP system:
EVAP vent valve: 15759044
EVAP vent valve connector: 12101858
Fuel tank pressure sensor connector: 88986451

Fuel system stuff:
Fuel pump module (note, will not fit in 88-95 tanks besides 4 door 95 Yukon/Tahoe): ACDelco MU146 (get it off ebay, much cheaper)
Fuel pump connector: 12167154

4L80e conversion parts:
Dipstick: 15183801
Dipstick tube: 15198439
Dust cover to use with 4.8, 5.3, 6.0L engines: 15765623

GMPP spark plug wires for LS1: 12495519

3 piece "Vortec 6000" engine cover, without hole for EGR valve on passenger side: 15006417, 15006418, 15006419

Mobil 1 oil filler cap: 12555685

If you are using a stock wiring harness and want to be able to remove it, you will need the following connectors:
C100 (engine to body harness): Delco PT1401
C152 (engine to chassis harness): GM 15306199
C153 (engine to 4WD harness): Delco PT420

6L engine gaskets/seals:
Front main seal- 12585673
Rear main seal- 12585671
Front cover gasket- 12574294
Rear cover gasket- 12574293
Top cover gasket- 12558178
Oil pan gasket- 12558760
Head gasket- 12589227
Valve cover gasket (2)- 12560696
Water pump gasket (2)- 12559271
Oil pickup tube o-ring- 12557075

6L engine internal parts:
Main bearings- 1,2,4,5: 89017469 each, 3: 89017470 each
Rod bearings-12493712 each
Valve seals- intake: 12482063 (8) , exhaust: 12482062 (8)
Valve keepers- 10166345 each

Some interesting facts about the GEN III engines including the LS1:

ENGINE: Liters: Cubic I: Bore: Stroke: Rod Length: Comp:
LR4 4.8 293 3.780 3.268 6.276 9.5
LM7 5.3 325 3.780 3.622 6.098 9.5
LS1 5.7 346 3.898 3.622 6.098 10.1
LS6 5.7 346 3.898 3.622 6.098 10.5
LQ4 6.0 364 4.00 3.622 6.098 9.4

Engine: HP TQ Application
LR4, 4.8L 255@5,200 285@4,000 '99 Silverado
270@5,200 285@4,000

LM7, 5.3L 265@5,000 320@4,000 '99 Silverado
285@5,200 325@4,000

LS1, 5.7L 305@5,200 335@4,000 '98-99' Camaro
335@5,200 335@4,000 '98-99' SS Camaro
345@5,600 350@4,400 '97-99 Corvette
350@5,600 350@4,400 2000 Corvette
350@5,600 375@4,400 '01 Corvette
350@5,600 360@4,000 '01 Corvette Auto
310@5,200 340@4,000 '01 Camaro Auto
325@5,200 350@4,000 '01 Camaro six-speed

LS6, 5.7L 385@6,000 385@4,800 '01 Corvette

LQ4, 6.0L 300@4,800 355@4,000
300@4,400 360@4,000
all ratings are up to 2001 models

Significant Gen III
Engineering Points:
1. All Gen III truck engines use iron blocks. Only the Camaro (F-Car) and Corvette (Y-car)LS1/LS6 engines feature aluminum blocks.

2. All Gen III engines have aluminum heads except for the '99 LQ4 engines that were equipped with iron heads. These engines received aluminum heads for the 2000 model year.

3. All Gen III engines share common main,rod,and cam-bearing journal diameters for ease of interchange. All blocks use a cross-bolted six-bolt main cap.

4. All Gen III engines are completely metric.

5. All valvetrain pieces are completely interchangable. The standard rocker ratio for all Gen III engines is 1.7:1.

6.All Gen III truck engines use cast aluminum oil pans that are deeper than the camaro or corvette pans.

7. All intake manifolds interchange. The truck intakes are roughly 3-4 inches taller than the passenger-car intakes.

8. All Gen III engines employ reusable gaskets for sealing surfaces except for the head gaskets. This makes it much quicker and easier to service the engine.

9. There are only two intake valve sizes for all the Gen III engines. Exhaust valves are all the same diameter.

10. Truck and camaro engines use cable throttle linkage while the corvettes use an electronic throttle. There are also some SUV engines with traction control that use electronic throttle control.

11. Bellhousing patterns are the same for all Gen III engines. The crank flange is basically the same depth as the bellhousing flange.

12. The Gen III firing order has been revised from 1-8-4-3-6-5-7-2 to 1-8-7-2-6-5-4-3. Note that the pairings 1-8, 4-3, 6-5, 7-2 remain the same, but the pairing order is different for reduced vibration.

13. The valve angle on all Gen III engines is 15 degrees versus 23 degrees for the origional and Gen II small-blocks.

14. The Gen III bore spacing is the same as the origional small-block, but each cylinder is ringed with only four head bolts instead of five.

Custom Cubes:
If you are fortunate enough to get your hands on an LQ4 6.0L engine block, you can bore it .030-over and purchase a 4.250 Lunati stroker crankshaft to produce a 434ci. GenIII engine.

Add a set of GM Performance Parts ZO6 cyclinder heads (PN 12560801) or have the stock LS1 heads ported and you've got yourself a serious engine.

All information is taken from Chevy High Performance Magazine May 2002 edition.

resource, and related part info ... 011001.htm ... _ls1.shtml ... apter=6065 ... 1884089844 ... shafts.php
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Staff member
Crankshaft Replacement Caution For
1998-2005 GM 4.8, 5.3, 5.7 & 6.0L Engines

The AERA Technical Committee offers the following information on crankshaft replacement caution for 1998-2003 GM 4.8, 5.3, 5.7 and 6.0L engines. Design changes in the flywheel flange thickness have been made to some crankshafts used in the above-mentioned engines. This bulletin is being re-published with additional information.

The later crankshafts are shorter on the flywheel flange as seen in the listing below. These changes are due to the many different vehicle / transmission combinations being built by GM.

A flywheel spacer ring GM Part #12563532 and a longer bolt set GM Part #12563533 is required when using a thin flange crankshaft to replace a thick flange crankshaft. Also, if the crankshaft is being used in a vehicle, which is a standard shift application, you also need pilot bushing GM Part #12557583 or 12479894.

Note: GM part numbers correct as of 12-18-04.

Years Liters Casting # Trans Flange Thickness

1999-2000 4.8L 312 V-8 M/T 1.250 thick flange
1999-2000 6.0L 215 V-8 1.250 thick flange
1999-2005 4.8L 482 V-8 A/T .857 thick flange
2001-2005 4.8L 482 V-8 M/T .857 thick flange
1999-2005 5.3L 216 V-8 A/T .857 thick flange
1997-2005 5.7L 216 V-8 .857 thick flange
2001-2005 6.0L 216 V-8 .857 thick flange

All GEN III crankshafts used in Camaro, Corvette and Firebird have a .857 thick flange and also have an expansion plug installed at the bottom of the pilot shaft hole. The 4.8, 5.3 + 6.0L don’t have the expansion plug. The drilled hole thru the centerline of the 5.7L LS1 & LS6 crankshafts allows a path to balance crankcase pressure within the lower crankcase. Doing so has eliminated possible oil consumption when the engine is operated over 4800 RPM.

Caution: Early crankshafts use a flat reluctor wheel and late have a recess. Recess will work on all years. Do not use a flat reluctor on late applications as it will cause an engine misfire.

The AERA Technical Committee

related info

Common Gen III V-8 Engine RPO Packages and Power Output
RPO Description
Liters (ci)
Power Output
HP/Torque Comp.
Ratio Chmbr.
Vol.(cc) Int/Exh.
Port Vol.(cc)
LS1 5.7 (346) car
GTO 350/365 345/340
305/335 to 325/350 10.19 67 200/70
LS6 5.7 (346) car Corvette 385/385 '01405/400 '02-today 10.46 65 210/75
LQ9 6.0 (364) truck/SUV
Escalade & Silverado SS 345/380 10.08 71 210/75
LQ4 6.0 (364) truck/SUV GMC/Chevrolet Fullsize 300/360 to 330/370 9.41 71 210/75
LM4 5.3 (325) truck/SUV '01 and later Fullsize, '04 SSR '04 Trailblazer/Envoy/ Bravada 290/325 to 300/335 9.49 61 200/70

LM7 5.3 (325) truck/SUV '99 and later Fullsize 285/325 to 295/330 9.49 61 200/70
LR4 4.8 (293) truck/SUV '99 and later Fullsize 270/285 to 280/290 9.47 61 200/70 ... index.html ... 8s/LS1.cfm


Staff member

Been wanting to get into the LS builds for some time but never been very happy with GM's platform but after lookiing into the new LS block Dart offers at the PRI show it has really changed my mind. It looks like I will be getting one of those new blocks and the tooling and programs needed to machine one of these blocks

Now for the big news… we’ve finished development on a brand new engine block for LS series engines!
The new block, dubbed the LS Next, unleashes the full potential of the LS platform. The new block will be available in cast iron or aluminum, and like all Dart products, will be 100% cast, machined and assembled in the U.S.A.

If you’re hungering for some technical details, look no further. Here’s a little info on what the new block will have going for it…

The power-robbing “Y-block” design is eliminated and replaced by a conventional SBC/BBC style crank barrel area
around the main caps, which eliminates the problem of separate bays in the crankcase.
Conventional style 4-bolt ductile iron or steel main caps with 7/16” bolts are used, and the block features full main
webbing for maximum bottom end strength.

Cylinder barrels are extended by .375” at the bottom, providing greater piston support with long stroke
combinations. This added piston skirt support allows for better piston designs to increase stability. Extra thick
Siamese cylinder bores allow for large displacement capacity.

The extended cylinder barrels provide the effective equivalent of a 9.615” deck height in terms of potential
supported piston travel, while maintaining a standard 9.240”actual deck height for maximum compatibility with
available components.

A 5/8” thick full deck design is utilized for superior strength and versatility. Six head bolts per cylinder provide
secure clamping for power adder applications. The head bolts are upgraded to 7/16” for increased strength. Blind
head bolt holes don’t go through into the water jacket.

Provision for oil restrictors in the lifter valley simplifies installation and removal of restrictors.
The stock internal main, or transfer, oil galley has been eliminated, and a revised low restriction priority main oiling
system is utilized. A pro-stock / pro-mod big block style stepped main oil galley, 9/16-1/2-7/16, has volume but
more importantly no loss of pressure or velocity at the front of the block. An external oil filter must be used with
stock or aftermarket oil pumps. A larger capacity full sump type oil pan is one of the key features.

Dual starter mounts allow mounting on either side for increased versatility.
The water jacket on the #1 cylinder has been expanded forward for better cooling.
LSX style lifter bosses and dog bone provision are provided.

Block Specifications:
Material: Gray Iron 220 BHN, Optional CGI up to 270 BHN
Deck Height: 9.240”
Barrel Length: Increased .375” over stock length
Bore Diameter: 4.000” or 4.125” – Can be safely bored to 4.200”
Max Stroke: 4.100”
Cam Bore: Std. – Options up to 60mm babbitt or 55mm roller
Main Bearing Size: Std. LS: Revised top shell
Main Caps: 4-Bolt, Ductile iron or steel – Splayed bolts on #2, 3 & 4
Rear Main Seal: Stock 1 piece
Lifter Diameter: Stock .842” –Other options to .937 keyed
Oiling system: True priority main – Wet or dry Sump



Staff member
ok, Ive got to ask what the thinking is in eliminating the extended (Y) lower block with its cross bolted main caps like this picture below, as this system has proven to be very durable on several engine designs

GM Engine Vin Codes
Anyone going out looking for a 4.8L or 5.3L Truck based LS engine that has already been removed from the vehicleBeware, Because unless you can look into the spark plug hole with a scope or little camera to see the top of the piston or insert a wire and run it across the piston surface to feel if it's dished or a flat top It's hard to tell the difference between those two. However if you look for the 8th digit in the VIN It will tell you most everything you need to know.

1999-2006 Trucks, Vans & SUV
, VIN. X or W(2003+) (8th digit)
6.0L, VIN. U (8th digit), (LQ4) Trucks, Vans and Denali
6.0L, VIN. N (8th digit) (LQ9) Escalades & SS Silverado
4.8L, VIN. V (8th digit)
5.3L, VIN. T (8th digit, opt LM7)
5.3L, VIN. Z (8th digit, opt L59)
5.3L, VIN. B (8th digit, opt L33 05+ HO Aluminum and Iron Block with 243/799 heads)

2007+ Trucks
classic body style, 6.0L, VIN. U (8th digit, opt LQ4), Compressed Natural Gas and Gasoline
classic body style, 6.0L, VIN. N (8th digit, opt LQ9)
classic body style, 4.8L, (VIN. V, 8th digit, opt LR4)
classic body style, 5.3L, VIN. T (8th digit, opt LM7)
classic body style, 5.3L, VIN. Z (8th digit, opt L59)
classic body style, 5.3L, VIN. B (8th digit, opt L33)
classic body style, 4.3L, (VIN. X, 8th digit, opt LU3)

new body style, 5.3L, (VIN. 0, 8th digit, opt LMG)
new body style, 5.3L, (VIN. J, 8th digit, opt LY5)
new body style, 5.3L, (VIN. 3, 8th digit, opt LC9)
new body style, 5.3L, (VIN. M, 8th digit, opt LH6)
new body style, 6.0L, (VIN. Y, 8th digit, opt L76)
new body style, 4.3L, (VIN. X, 8th digit, opt LU3)
new body style, 4.8L, (VIN. C, 8th digit, opt LY2)

2003-04 GMC Truck Envoy XL
2003-04 Isuzu Ascender
2003-04 Chevy TrailBlazer EXT (all with VIN "P", 8th digit)
2005-06 (all with VIN "M", 8th digit)
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Staff member

but dry sump lubrication systems are preferred if the budget allow on the race applications, as it potentially provides greater control under higher inertial side -loads ... tId=748533

LS2 does not have a dry sump as standard equipment from the factory.

Any LS2 sump will bolt onto a LS1...LS1 sump gasket will fit... just need to use the oil pickup tube that belongs to the sump.

The LS2 sump to suit a C6 corvette has internal baffles to contain the oil better during cornering.....gone are the "batwings" seen on C5.

The LS2 sump to suit an 05 GTO looks identical externally to the LS1 GTO sump.

LS2 oil pump has better flow than LS1 but is in same position and at a glance looks the same externally. LS1 and LS2 oil pickup tubes may differ in length and position in the sump but have same tube size and O ring seal to the pump.




Re: CHEVY LS1 related inf

I think still a Y Block design has strength durabilty advantages Grumpy.
Think 440 Mopar.
426 Hemi.
Oil windage issues are Moot in an all out Drag Race or Road Race.
Its going to be dry sumped anyhow.
The Heads on aftermarket LS Engines are so nice.
Excellent bang for the buck value.


Staff member

just so others can look over the test results, on those ls intakes

both cross sectional area, and length effect flow but remember, displacement compression and cam timing also are major factors.
what most people fail to take into account is that the cam timing and exhaust scavenging being properly matched is critical.
changing the cam timing or header configuration would change some of the resulting intake flow rankings .
tests like that are helpful, as a basic parts selection guide and starting point,
but you can,t assume the results will remain consistent on different engines.
I'd also point out that component cost and easy packaging,
and parts availability all are significant choices and factors,
that were used in the components used.




various LS series oil pans ... tId=748533

LS Oil Pump Specifications 1.jpg

a few tips on installing a manual trans behind an LS series engine in an older muscle car, and identifying that LS engine ... r_ls_swap/ ... 8_engines/












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solid fixture here in the forum
good info on the trany pans... very important for people wanting to do a swap.

of note if you need it i believe the GTO was a front sump design for the guys that need that setup in their specific application and dont know where to get a pan.


Staff member
Brian Hoss said:
The topic of “what pan do I buy” has come up many times. While there are plenty of options out there, few actually fit the A-body. I would like this thread to be about ACTUAL fitment and questions related to those who have spent the time to test fit. The pan is only part of the equation. To correctly identify fitment, adaptor plates, engine (motor) mounts and frame mounts must also be given.

The other side of this is doing something that you will regret later and that’s changing the driveline angles. In this case, the easy fix to get some of these pans to fit is to just raise the engine up. While that will normally correct your pan/crossmember/tie rod end clearance problem, you’re creating a huge mess for the alignment of the trans/driveshaft/differential. I would never recommend altering the engine placement as a temporary fix. I would never build a car like this and I won’t here either. All the mounts are at their factory location or where the parts place them. No spacers or other mods (frame notching) are acceptable for my build.

I’ll start. Here is what I have found for the 66-67 Chevelle/El Camino;

Here is the mounting information;
Dirty Dingo Sliders (LS adaptor plates) part # DD-SLIDER
Energy Suspension LS conversion kit 3.1148 (this was the first kit I used until I switched to the DD sliders)
Energy Suspension engine/motor mounts part number 3.1114
Factory small block Chevy frame mounts GM part number ?

I have three pans that I tried in my 67 El Camino and my 67 Chevelle. Also, for MAXIMUM clearance, the sliders are all the way back towards the firewall. This helps the sump to crossmember clearance.

Factory truck pan from 2002 Silverado 6.0L
2008-2015 Cadillac CTS-V pan GM 12065818
Canton Racing Products road race baffled pan 15-274

Here are all three pans together for a visual comparison. Picture 1 has the pans labeled so you can follow them in the following pictures. The truck pan has some significant differences in dimension as compared to the CTS-V and the Canton pan. The CTS-V and Canton pans have some similarities and some glaring differences that will become evident in the fitment pictures. (Pictures 1-6)







Brian Hoss said:
First is the truck pan installed. The obvious problem here is the sump hangs well below the crossmember. Oddly enough, it will fit with the mounts used and bolt up. Some serious modifications are needed to clearance the sump and bring it up to at least the line of the cross member, and the engine will have to be raised to clearance the tie rod ends. This would require the most cut and weld project of the two aluminum pans. (Picture 1)

Next is the ever popular CTS-V pan. While it certainly comes close to fitting, the issue is the transition from the front of the pan to the sump. It hits on the cross member and will not allow the engine to fully seat onto the engine mounts. Here is where some will space the engine mounts and raise the engine up to generate the needed clearance. The problems with this are listed above. Now this pan can be cut up and rewelded to get the proper fitment for the transition, however it will still require the engine be raised to clear the tie rod ends. (Pictures 2-5)

Last is the Canton pan. This pan is a home run on two fronts. One, it fits. Two, it fits with a 4.25 steel rod stroker kit. The truck and CTS-V pans can be clearanced for the added stroke, but there is some fabrication required. The Canton pan works in the three critical areas. Tie rod end clearance, pan to crossmember clearance and no alterations to the engine height. The added bonus is the clearance for a stroker. (Pictures 6 - 7)

If you have confirmed fitment or non-fitment of any other pans out there, please provide details on the pan, engine mounts and pictures.









solid fixture here in the forum
i wonder how tall that lip is in the front of the motor... the f body pan is like 1 and 1/3" there, as far as i know nothing is that thin.


The Grumpy Grease Monkey mechanical engineer.
Staff member
Cylinder Heads and Casting Numbers

Briggs told us that “The 317 casting number truck head is pretty hard to beat. It’s actually a pretty good head when it comes to boost because of the bigger combustion chamber.” We checked the 317 casting number flow numbers out and found that they are pretty much the same flow as the LS6 heads. For a budget friendly junkyard build, these heads are a pretty good deal, but only if you are planning on using a power adder like a turbo or supercharger.

An LS6 style head is good for naturally aspirated applications because of the smaller combustion chamber. L92 cylinder heads have become very popular additions to the LQ4/LQ9 iron truck blocks because of their flow. The L92 heads have proven themselves to be rockets based on the racing influenced design of the heads which have raised runner floor and wider port opening by virtue of an offset intake pushrod. Golen believes that “it’s worth the time and effort to find a set of L92 heads for your cast iron block. There are big horsepower gains that can be made with that combination.”
Here’s a quick rundown on the LS cylinder heads by casting numbers:

Casting Number 12564241 or 12559853

  • 1997-2003 LS1 Passenger Cars
  • Aluminum
  • Combustion Chamber Volume: 66.67cc
  • Compression Ratio: 10.1:1
  • Intake Port Volume: 200cc
  • Exhaust Port Volume: 70cc
  • Intake Valve: 2.00”
  • Exhaust Valve: 1.55”
  • Part #12559853 (1997-2000), 12564241 (2001-2003)
Casting Number 12564243

  • 2001 LS6 Passenger Car
  • Aluminum
  • Combustion Chamber Volume: 64.45cc
  • Compression Ratio: 10.5:1
  • Intake Port Volume: 210cc
  • Exhaust Port Volume: 75cc
  • Intake Valve: 2.00”
  • Exhaust Valve: 1.55”
  • Part #12564243
Casting Number 12562317 or 12572035

  • 2001-2004 LQ4/LQ9 equipped truck
  • Material: Aluminimum
  • Combustion Chamber Volume: 71.06cc
  • Compression Ratio: 10:1
  • Intake Port Volume: 210cc
  • Exhaust Port Volume: 75cc
  • Intake Valve: 2.00 inches
  • Exhaust Valve: 1.55 inches
  • Part Number: 12572035
Casting Number 12561873

  • 1999-2000 LQ4 equipped truck
  • Material: Cast Iron
  • Combustion Chamber Volume: 71.06cc
  • Compression Ratio: 9.5:1
  • Intake Port Volume: 210cc
  • Exhaust Port Volume: 75cc
  • Intake Valve: 2.00 inches
  • Exhaust Valve: 1.55 inches
Casting Number 12561706 or 12559852

  • 1999-2004 LR4 equipped truck
  • Material: Aluminum
  • Combustion Chamber Volume: 61.15cc
  • Compression Ratio: 9.5:1
  • Intake Port Volume: 200cc
  • Exhaust Port Volume: 70cc
  • Intake Valve Diameter: 1.89 inches
  • Exhaust Valve Diameter: 1.55 inches
  • Part Number: 12559852, 12561706
Casting Number 12558806 or 933

  • 1997-1998 LS1 (Perimeter Bolt) Passenger Car and Corvette
  • Material: Aluminum
  • Combustion Chamber Volume: 66.67cc
  • Intake Port Volume: 200cc
  • Exhaust Port Volume: 70cc
  • Intake Valve Diameter: 2.00 inches
  • Exhaust Valve Diameter: 1.55 inches
Casting Number 2716 and 5364

  • 2008+ LS3/L92 Passenger cars and Corvette
  • Material: Aluminum
  • Combustion Chamber Volume:68.4cc
  • Intake Port Volume:257cc
  • Exhaust Port Volume:86cc
  • Intake Valve Diameter:2.165 inches
  • Exhaust Valve Diameter:1.59 inches
love302chevy said:
Here are a few Howards camshafts I think will work:

Howards Cams, Hydraulic Roller Camshaft, Chev LS Gen III/IV 3-Bolt, 204/210 @ .050, .525/.525 114 LS

Howards Cams Hydraulic Roller Camshaft, Chev LS Gen III/IV 3-Bolt, 207/213 @.050, .556/.566 114 LS

Howards Cams, Hydraulic Roller Camshaft, Chev LS Gen III/IV, 208/214 @ .050, .525/.525 114 LS

Howards Cams, Hydraulic Roller Camshaft, Chev Gen III/IV LS-Series 3-Bolt, 210/214 @ .050, .595/.598 108 LS

Howards Cams, Hydraulic Roller Camshaft, Chev Gen III/IV LS Series 3-Bolt, 214/220 @ .050, .525/.525 112 LS

Howards Cams, Hydraulic Roller Camshaft, Chev Gen III/IV LS-Series 3-Bolt, 218/218 @.050, .604/.604 113 LS
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I worked on the Dart LSN126 427 CI 1500HP Engine today Grumpy.
Had to leave early.
The 2 year old boy Jami has Pink Eye.
Driving home 90+.
Wife has to go in to do emergency IT work.

Vette has been apart 1-1/2 years.
Pressure is on me 410%.
Must be done by this Friday.
Drive away.

Insanity again.

Valve stem height varience present.
Verified with my Snap On machinest straight edge.
Recorded photographed.
Lifter preload critical as you lnow.
Shooting for .025-.030".
Non adjustable rockers.
.025" Shims under pedstals.

Give me LS Race valvetrain links today.
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I figured out what Rockers I am working with Grumpy.
Searched the LS Board Forums.
Spider web search.

Yellow Terra LS3/LS9/LSA/L92 Ultra Light 1.8 Rockers.

Why in the Hell would not GM Chevy LS Engineering make the Valvetrain fully adjustable like a Big Block Chevy & 1970 Pontiac Ram Air 4 ? !

A Damn Shit Design on all LS.



I Google Yella Terra YT-6681 PRICE..




Its no wonder Phil can't build a modern Race LS Engine.
Can't afford to.

I am glad I am a Pontiac V8 Guy.


Its looking like the Entire LS Line of engines were designed with factory Hydraulic lifters used have .075" -.150 " preload setting from Zero Lash.

M8 X 1.25 mm thread pitch bolts on the rocker arm shafts used.

Take 1.25 mm ans divide by 25.4.
Equals .049 " .

1 Turn down equals .049" lifter plunger seat preload.

1-1/2 turns equals .075 " .
3 turns equals .150"

1-1/2 -3 turns down from zero lash required in theory Grumpy.


The Grumpy Grease Monkey mechanical engineer.
Staff member

purchasing a few reference books and carefully







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