Planning to build yourself that monster LT1/LT4 motor next week? Might want to check out these old notes Slowrider found on his hard drive the other day... Compression Height (Probably the hardest info of all to find) ------------------------------------------------------------- To calculate the piston Compression Height, use the following formula: Block Height (LT1/LT4 = 9.025") minus 1/2 the crank stroke (which is 3.480 for the LT1/LT4), minus the rod length (which is 5.7" for the LT1/LT4), minus the deck clearance (amount piston is "in the hole" which is apx 0.017" for the LT1/LT4). For example, a stock 5.7L/350ci Chevy engine (including LT1/LT4 engines) with a stock 3.480 stroke, stock length 5.700 rod, standard .017 deck clearance and standard 9.025 block height would be: 3.480 stroke divided by 2 = 1.740 9.025 - 1.740 - 5.700 - .017 = Compression Height of 1.568. For a 392ci engine these numbers should work... Block Height (if decked .015") = 9.010" 1/2 Crank stroke = 1.9375 Rod Length = 5.875" or 6.000" (depends on the piston dish allowances) Deck clearance = .002" 9.010 - 1.9375 - 6.000 - .002 = Compression Height of 1.0705 (w/6.000" rod) 9.010 - 1.9375 - 5.875 - .002 = Compression Height of 1.1955 (w/5.875" rod) Head Casting Numbers LT1/LT4 ---------------------------- 10207643 is most common LT1 apparently 10128374 similar to 643 12551561 perhaps better flowing LT1 (closer to LT4) but less material to port supposedly xxxxx287 LT4 xxxxx690 LT4 xxxxx902 LT4 xxxxx843 LT4 Basic Engine Specs ------------------ 350ci = 349.848ci actual w/4.000" bore and 3.480" stroke (stock LT1) 5.700" rods & 3.999" dia pistons w/4.000" rings & 0.3" land Compression ratio: 10.5:1 w/56cc chamber & 0.049" gasket 355ci = 355.115ci actual w/4.030" bore and 3.480" stroke 5.700" rods & 4.029" dia pistons w/4.030" rings & 0.3" land Compression ratio: 10.9:1 w/54cc chamber & 0.049" gasket Compression ratio: 10.8:1 w/55cc chamber & 0.049" gasket Compression ratio: 10.6:1 w/56cc chamber & 0.049" gasket 357ci = 356.880ci actual w/4.040" bore and 3.480" stroke 5.700" rods & 4.039" dia pistons w/4.040" rings & 0.3" land Compression ratio: 11.0:1 w/54cc chamber & 0.049" gasket Compression ratio: 10.8:1 w/55cc chamber & 0.049" gasket Compression ratio: 10.7:1 w/56cc chamber & 0.049" gasket 360ci = 360.422ci actual w/4.060" bore and 3.480" stroke 5.700" rods & 4.059" dia pistons w/4.060" rings & 0.3" land Compression ratio: 11.1:1 w/54cc chamber & 0.049" gasket Compression ratio: 10.9:1 w/55cc chamber & 0.049" gasket Compression ratio: 10.8:1 w/56cc chamber & 0.049" gasket 377ci = 376.991ci actual w/4.000" bore and 3.750" stroke 5.700" rods & 3.999" dia pistons w/4.000" rings & 0.3" land or 6.000" rods & 3.999" dia pistons w/4.000" rings & 0.3" land Compression ratio: 11.5:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.4:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.2:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.1:1 w/57cc chamber & 0.049" gasket 383ci = 382.667ci actual w/4.030" bore and 3.750" stroke 5.700" rods & 4.029" dia pistons w/4.030" rings & 0.3" land or 6.000" rods & 4.029" dia pistons w/4.030" rings & 0.3" land Compression ratio: 11.7:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.5:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.4:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.3:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.1:1 w/58cc chamber & 0.049" gasket Note: My motor with -16cc dished pistons, 0.039" gasket and 56cc chamber should be about 9.8:1 to 10.2:1 CR 385ci = 384.569ci actual w/4.040" bore and 3.750" stroke 5.700" rods & 4.039" dia pistons w/4.040" rings & 0.3" land or 6.000" rods & 4.039" dia pistons w/4.040" rings & 0.3" land Compression ratio: 11.7:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.6:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.4:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.3:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.2:1 w/58cc chamber & 0.049" gasket 388ci = 388.386ci actual w/4.060" bore and 3.750" stroke 5.700" rods & 4.059" dia pistons w/4.060" rings & 0.3" land or 6.000" rods & 4.059" dia pistons w/4.060" rings & 0.3" land Compression ratio: 11.8:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.7:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.5:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.4:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.3:1 w/58cc chamber & 0.049" gasket 390ci = 389.577ci actual w/4.000" bore and 3.875" stroke 5.700" rods & 3.999" dia pistons w/4.000" rings & 0.3" land or 6.000" rods & 3.999" dia pistons w/4.000" rings & 0.3" land Compression ratio: 11.9:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.8:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.6:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.5:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.4:1 w/58cc chamber & 0.049" gasket 395ci = 395.423ci actual w/4.030" bore and 3.875" stroke (396) 5.700" rods & 4.029" dia pistons w/4.030" rings & 0.3" land or 6.000" rods & 4.029" dia pistons w/4.030" rings & 0.3" land Compression ratio: 12.0:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.9:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.7:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.6:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.5:1 w/58cc chamber & 0.049" gasket 397ci = 397.388ci actual w/4.040" bore and 3.875" stroke 5.700" rods & 4.039" dia pistons w/4.040" rings & 0.3" land or 6.000" rods & 4.039" dia pistons w/4.040" rings & 0.3" land Compression ratio: 12.1:1 w/54cc chamber & 0.049" gasket Compression ratio: 11.9:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.8:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.6:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.5:1 w/58cc chamber & 0.049" gasket 401ci = 401.332ci actual w/4.060" bore and 3.875" stroke 5.700" rods & 4.059" dia pistons w/4.060" rings & 0.3" land or 6.000" rods & 4.059" dia pistons w/4.060" rings & 0.3" land Compression ratio: 12.2:1 w/54cc chamber & 0.049" gasket Compression ratio: 12.0:1 w/55cc chamber & 0.049" gasket Compression ratio: 11.9:1 w/56cc chamber & 0.049" gasket Compression ratio: 11.8:1 w/57cc chamber & 0.049" gasket Compression ratio: 11.6:1 w/58cc chamber & 0.049" gasket 423ci = 423.026ci actual w/4.040" bore and 4.125" stroke Pounder crank 6.000" rods & 4.039" dia .030" dished pistons w/ short skirts, 4.040" rings & 0.3" land Compression ratio: 12.1:1 w/58.5cc chamber & 0.049" gasket 1993-1997 LT1 Service Manual Engine Assembly Specs -------------------------------------------------- Per the GM manual the stock bearing specs are a little strange, but perhaps that explains why the oil pressure is better in an engine before it gets reamed out by some builder who has no clue how to blue print an LT1 engine? Crank Main Journal Dia #1 62.189 to 62.212 mm (2.4484 to 2.4493") #2 62.182 to 62.205 mm (2.4481 to 2.4490") #3 same as #2 #4 same as #2 #5 62.177 to 62.120 mm (2.4481 to 2.4488") Out of round Max Prod 0.005 (0.0002") Service 0.025 mm (0.0010") Crank Bearing Clearances #1 0.020 to 0.051 mm (0.0008 to 0.0020") #2 0.028 to 0.051 mm (0.0011 to 0.0020") #3 same as #2 #4 same as #2 #5 0.043 to 0.081 mm (0.0017 to 0.0032") Crank Assembly End Play 0.03 to 0.17 mm (0.001 to 0.007") Connecting Rod Journals Dia 53.068 to 53.334 mm (2.0893 to 2.0998") Out of round Max Prod 0.013 (0.0005") Service 0.025 mm (0.0010") Rod Bearing Clearance Prod 0.033 to 0.088 mm (0.0013 to 0.0035") Service 0.076 mm (0.0030") Max Rod side clearance 0.16 to 0.35 mm (0.006 to 0.014") ----- Per a Blue Printing book I have... Rod bearing clearance .0020 to .0025" Side clearance .010 to .020" Main Bearing .0020 to .0030" clearance .005 to .007" end play ----- Other TQ specs you might need... Balancer bolts - 85 Nm, 63 lb ft Balancer hub bolt - 100 Nm, 74 lb ft Cam retainer screws - 12 Nm, 105 lb in (8.75 lb ft) Cam sprocket bolts - 25 Nm, 18 lb ft Coil bolt - 40 Nm; 30 lb ft Coolant bleed pipe bolt - 40 Nm, 30 lb ft Crank bearing cap bolt - 88 Nm, 63 lb ft Cyl head bolts - 88 Nm, 65 lb ft Distr/OPTI bolt - 12 Nm, 106 lb in (8.8 lb ft) Eng mount bolts - 80 to 95 Nm; 60 to 70 lb ft Eng mount to frame - 58 Nm; 43 lb ft Eng pulley bracket bolt - 58 Nm, 43 lb ft Flywheel bolt - 100 Nm; 74 lb ft Front cover bolt - 11 Nm, 100 lb in (8.3 lb ft) Fuel rail bolt - 10 Nm 90 lb in (7.5 lb ft) Generator bracket bolt - 40 Nm; 30 lb ft Intake manifold bolt (pass one) - 8 Nm; 71 lb in (6 lb ft) Intake manifold bolt (pass two) - 48 Nm; 35 lb ft Knock sensor - 20 Nm; 15 lb ft Lifter retainer bolts - 25 Nm; 18 lb ft Oil cooler adapter bolt - 25 Nm; 18 lb ft Oil cooler bolt - 33 Nm; 24 lb ft Oil cooler hose bracket nut - 17 Nm; 13 lb ft Oil filer adapter bolt - 23 Nm; 17 lb ft Oil level sensor - 22 Nm; 16 lb ft Oil pan corner bolts - 20 Nm; 15 lb ft Oil pan side bolts - 12 Nm, 106 lb in (8.8 lb ft) Oil pres sender - 12 Nm; 105 lb in (8.75 lb ft) Oil pump cover bolt - 9 Nm; 80 lb in (6.7 lb ft) Oil pump DS bolt - 18 Nm; 13 lb ft Oil pump to bearing cap bolt - 90 Nm; 66 lb ft Rear main seal housing nut and bolt - 15 Nm, 11 lb ft Rocker stud - 68 Nm; 50 lb ft Rod nuts - 27 Nm ,20 lb ft + 55 deg turn Spark plugs - 15 Nm; 11 lb ft Starter motor bolts - 47 Nm; 35 lb ft TB bolts - 25 Nm; 18 lb ft Valve cover bolts - 12 Nm, 106 lb in (8.8 lb ft) Water pump bolts - 41 Nm; 30 lb ft Water pump DS bearing retainer bolts - 12 Nm, 106 lb in (8.8 lb ft) How To Compute Compression Ratio 101 ------------------------------------ To correctly compute your new motor's compression ratio you will need to have some conversion information and some understandable formulas. And you'll need to have a couple geometry equations as they relate to the volume of a cylinder, etc. Plus, you are going to have to figure out the volume of your combustion chambers in your heads, etc. in cubic centimeters (the standard unit of measure for such things). First some definitions of the basic variables involved... 1 inch = 1/12 x 1ft where "in" stands for inch 1ci = 1in x 1in x 1in where "ci" stands for cubic inch 1 centimeter = apx 0.39375in where "cm" stands for centimeter 1cc = 1cm x 1cm x 1cm = 0.39375in x 0.39375in x 0.39375in = apx 0.061025 ci where "cc" stands for cubic centimeter There are apx 16.387cc in 1ci (1 / 0.061025) Top Dead Center = TDC This is where the piston is at the top of each stroke or cycle within the engine bore. Bottom Dead Center = BDC This is where the piston is at the bottom of each stroke or cycle within the engine bore Stroke (or Height) = S S = 3.875 for 396 stroke This is the crank stroke length or distance (in a 350ci motor it is 3.48in and in a 383ci motor it is 3.75in usually and will depend on whatever crank you are using) Diameter = D D = 4.010 for 392 This is the cylinder diameter or longest distance across D = 4.005 for 391 the cylinder bore circle Radius = R = D / 2 R = 2.005 for 392 R = 2.0025 for 391 Swept Volume = SV This is the volume of the cylinder defined by the piston top face plane between TDC and BDC and may be expressed as SV = pi x R^2 x S SV = pi x 2.005^2 x 3.875 = 48.9384639 ci for 392 SV = pi x 2.0025^2 x 3.875 = 48.8164989 ci for 391 NOTE: The volume of a cylinder is normally written as V = pi x R^2 x H where pi = apx 3.1416 (a constant) NOTE: SV = 43.731072ci in a 350 motor (349.848ci actual) and SV = 48.9384639 / 0.061025 = 801.94123561 cc SV = 47.833510725ci in a 383 motor (382.668ci actual) and these values convert to 716.62108cc in a 350 motor and 783.84774cc in a 383 motor Clearance Volume = CV This is the volume of the space created inside the so call CV = 81.830738 cc will yield a CR of 10.8:1 via... "combustion chamber" space when the piston is at TDC and is generally the area created between the piston top plane 10.8 = (801.94123561 + CV) / CV face minus any piston crown volume, plus any piston dish 10.8 * CV = 801.94123561 + CV volume, valve relief volume, excess cylinder wall height 10.8 * CV - 1 * CV = 801.94123561 above the piston top, the minor area above the seal ring top 9.8 * CV = 801.94123561 surface and between the piston wall and cylinder wall, the CV = 801.94123561 / 9.8 gasket seal area and the head chamber area (all of which are CV = 81.830738 difficult at best to measure or obtain but which can usually be estimated fairly closely) Combustion Chamber (CCH) will be... CV - (18.25 cc dish/reliefs) - (gasket volume area) - 1 cc ring vol Compression Ratio = CR = (SV + CV) / CV This is the ratio of the volume of the space created when Gasket ave diameter = 4.135 in the piston is at BDC (SV + CV), and which is filled by the Gasket height = 0.039 in intake air-fuel mixture, to the volume of the space created Gasket Volume (GV) = pi x (4.135 / 2)^2 x .039 when the piston is at TDC (CV), and the intake air-fuel GV = .523728 ci mixture is then ready to ignite GV = .523728 / 0.061025 GV = 8.582182 cc NOTE: It is possible to solve this equation for one unknown variable if you know the other two such that you can CCH = 81.830738 - 18 - 8.582182 - 1 find CV = SV / (CR - 1) if you know CR and SV... for CCH = 54.25 cc (I'll shoot for 54cc heads) example CV = 716.62108cc / ((10.5 / 1) - 1) = 75.4338cc Per Bowling & Grippo Automotive Calc NOTE: Another way to think of this might be to take a typical * Cylinder head Volume (CC) = 54.00 stock 350 LT1 motor, with a known compression ratio # Piston Top Volume (CC) = 18.00 of apx 10.5:1 and with 56cc combustion chambers in its # Cylinder Bore (Inches) = 4.0 stock LT1 heads, it stands to reason that its CV = # Cylinder Stroke (Inches) = 3.88 716.62108cc / 9.5... that is its CR = (9.5 + 1) / 1 # Deck Height (Inches) = 0.000 so, by deduction, its SV is a magnitude of 9.5 greater * Head Gasket Thickness (Inches) = 0.040 than its CV (as in 9.5 / 1 = 716.62108cc / CV) which, # Computed Compression Ratio is 11.0 to 1 when solved for CV, yields CV = 75.4338cc... of which 19.4338cc is the remaining part of the combustion volume NOT in the combustion chamber area of the LT1 heads... Hydraulic Roller Camshafts -------------------------- Camshaft design is one of the most important factors to consider when building your EFI engine. To help you make the right decision, LPE has designed several camshaft profiles to maximize the power potential of your EFI engine for use with stock LT1 intake manifolds. Some of these camshafts are not compatible with stock computer programs and will require (HPP+?) software changes. All of the hydraulic roller cams are produced from a hardened steel core with a unique pressed on cast iron distributor gear. This eliminates the need for a special bronze distributor gear which must be replaced frequently due to the soft material. Camshafts will produce a good idle at 750 RPM unless marked otherwise. Hydraulic roller cams may be used with the stock hydraulic roller lifters after careful inspection for wear. Some late model applications require a longer drive pin #10214485. Summit duration to powerband rpm range estimate: 206-220 1500-4500 rpm 221-230 2000-5500 rpm 231-234 2500-6000 rpm 234-238 3000-6500 rpm 239-244 3500-7000 rpm 245-255 4000-7000 rpm Hydraulic Roller Camshafts @ LPE Engine/RPM Induction Dur @.050" Lift w/ 1.5 Lift w/ 1.6 Sep Cam SBC 305-383 LT1 211/219 .499"/.525" .533"/.560" 112 74211 $314.95 ????-???? SBC 305-420 LT1 213/219 .462"/.471" .493"/.502" 112 74216 $314.95 ????-???? Comp Cams LT-1 hydraulic roller camshaft @ IRS SBC 305-383 LT1 210/220 .500"/.510" 114 07-304-8 $239.95 2000-5500 SBC 305-383 LT1 220/230 .510"/.510" 114 07-305-8 $219.95 +? 2500-6000 SBC 305-383 LT1 230/244 .510"/.540" 112 07-306-8 $219.95 + 2500-6500 Comp Cams LT1 Xtreme Energy Cams @ IRS SBC 305-383 LT1 224/230 .503"/.510" 112 224-230-12 $239.95 +? 1900-5600 SBC 305-383 LT1 230/236 .510"/.521" 112 230-236-12 $239.95 ++ 2200-5800 SBC 305-383 LT1 236/242 .521"/.540" 112 236-242-12 $239.95 2500-6000 GTP 421 Comp Cam @ ??? SBC 305-383 LT1 220/234 .510"/.510" (sm base cir) 114 ??-???-?? $???.?? ++ ????-???? GM Performance Parts camshafts @ IRS 5.7L HO 350 ZZ3 Cam 208/221 .474"/.510" 112 10185071 $209.99 ????-???? LT-4 Hot Cam 218/228 .525"/.525" 112 24502586 $209.99 +? ????-???? 5.7L Off-road use 214/224 .488"/.509" 112 12370845 $254.99 ????-???? 5.7L Off-road use 222/230 .509"/.528"? 112 12370846 $254.99 +? ????-???? 5.7L Off-road use 232/242 .539"/.558"? 112 12370847 $254.99 ++ ????-???? PCM Reprogramming Sources ------------------------- Ed Write through IRS $500+ PCMdoc@surfree.com Jones Electronic Technologies (JET) Mad Man Racing, Houston, TX TPIS 612-448-6021 $575 Atlanta Chassis Dyno 770-623-9789 TTS Power Systems 310-669-8101 The Turbo Shop 310-669-8101 Pro Auto Tech http://www.proautotech.com/ PCM Programming $525.00 Sale Price $495.00 Located in FL (verify not Jim Famato???) Hypertech 1-800-532-3351 $210 (Not customized per each cam) Z-Industries custom computer chip Lingenfelter Shalin Patel - Custom Computer Tuning $350? via evan@lt1.net IRS 1-888-469-7223 (Jamie) $500 to send the ECM to FL (couple weeks) http://www.tecinfo.com/~rsguy2/page2.htm scott rowe has Motorsports Tech Inc ECM with CC306 --------------------------- Comp Cams Help 1-800-999-0853 or Scott Vincent 1-800-365-9145 x568 (or Mark ???) GM High Tech Performance www.gmhitechperformance.com --------------------------- Extra PCM for Reprogramming Beltsville Auto Recycling, MD $75 + $10 shipping. Martin 301-937-7333. --------------------------- LT1 Edit/PCM Links: http://www.lt1.net/editor/Lt1edit.htm http://www.tecinfo.com/~rsguy2/page2.htm http://www.tir.com/~steveher/lt4.html http://www.io.com/~jme/z28/ http://www.fbody.com/wayne LPE = Lingenfelter IRS = Internet Racing Supply THR = Thunder Racing 350/355/360 ------------ Clevite 77 bearings Hand port intake manifold 58mm throttle body (52mm optional) Terminator Series Stage I Ported LT1 Cylinder Heads @ IRS Each pair of Stage I ported LT1 cylinder heads are disassembled cleaned and inspected for defects. They then receive a complete pocket port and bowl clean-up, both intake and exhaust port openings are gasket matched to ensure a smooth transition from the manifold to the cylinder head. A multi-angle competition valve job is next with a back-cut on the valves. Each cylinder head is then resurfaced to ensure a good gasket seal between the head and block. Heads include... Manley stainless steel Race-Flow valves - 1.94" intake x 1.50" exhaust GM dual valvesprings Valve spring retainers (double check titanium) (no studs?) (no guide plates?) Spring seats Valve seals Locks IRS-ST1LT1H $899.00 (w/exchange) CNC Ported Cylinder Heads Package @ THR --------------------------------------- These precision CNC machined cylinder heads will guarantee maximum flow and horsepower. A 5 axis (simultaneous) precision CNC machine is used to literally make these cylinder heads look like jewels. Set up for use with self-aligning rocker arms (Part # 40-10758-16 or 40-10751-16, below). Heads include... REV stainless steel valves - 2.00" intake x 1.57" exhaust REV valve springs (double check this) Valve spring retainers (double check titanium) ARP 3/8" studs Guideplates (double check type) Spring seats Valve seals Heat treated locks $1,550.00 (w/exchange) GTP Stage II Ported Cylinder Heads @ IRS ---------------------------------------- Stage II Cylinder heads receive complete porting and polishing of the intake and exhaust ports, bowls and combustion chambers, competition multi-angle valve job w/backcut valves, resurface of head to ensure a good gasket seal. Heads include... Ferrea severe duty stainless steel 2.00" x 1.56" valves Competition Cams dual valvesprings Valve spring retainers (double check titanium) Studs (check stud size) Guideplates (double check type) Spring seats Valve seals Locks GTP-LT1H $1799.00 (w/exchange) CNC Ported Large Cam Cylinder Heads Package @ THR ------------------------------------------------- Same as above with additional features and set up for use with non-self-aligning rocker arms (Part # 40-11752-16 or 40-11755-16, below). Valve springs shimmed to correct installed height. Castings machined for larger springs and spring seats. Heads include... REV stainless steel valves - 2.00" intake x 1.57" exhaust Crane Dual-Coil valve springs Crane titanium Posi-Stop valve spring retainers ARP 7/16" studs Crane stepped guideplates I.D. locator spring seats (No valve seals?) Hardened locks $2,000.00 (w/exchange) CNC Ported Cylinder Heads Package @ LPE --------------------------------------- The LT1 Aluminum cylinder head, like its predecessor the D-Port, will produce the best usable horsepower and torque on 350 & 383 LT1 engines. The CNC Ported LT1 cylinder head works well with the original intake ported. This is the same head that is install on LPE 440hp 383cid LT1 engines. Heads include... Stainless steel one piece valves - 2.00" intake x 1.56" exhaust Heavy duty double valve springs (double check this) Titanium valve spring retainers ARP studs (check stud size) Guideplates (no spring seats?) Valve seals (no locks?) $2,199.00 ------------------------------------------------- Cloyes 2 pc timing chain front cover PN 9-221 $86!! 1-800-233-0199 1-920-233-2023 LT1 Cylinder Head Swap Gasket Package @ THR ------------------------------------------- This package covers most needed gaskets for top end rebuild. Does not include timing chain cover, seals, misc. GM Cylinder Head Gaskets (exact gasket will depend on application) GM Intake Manifold Gaskets GM Exhaust Manifold Gaskets or FelPro Header Gaskets GM EGR Gaskets (depending on application) GM Valve Cover Gaskets GM Throttle Body Gasket GM Cylinder Head to Coolant Gaskets (water pump?) $155.00 Other Valve Springs ------------------- IRS-9397V Terminator Series Dual springs for cams <= .550 lift @ IRS $89.95 10308-1 Crane Dual springs for cams <= .600 lift @ IRS $155.95 Heavy Duty Push Rods, Studs & Guide Plates ------------------------------------------ Pushrods that are made from chromemoly tubes and are heat treated and have welded tips to provide long life. Recommended for LT1 applications with heat treated guideplates. LN0280H-SBC 5/16" dia Hyd Roller @ LPE $34.95 7940-16 Comp Cams Hi-Tech 5/16" Chromemoly 1993-97 LT1 @ IRS $99.99 4500-16 Comp Cams 3/8" Screw-in Rocker Arm Studs @ IRS $27.95 4501-16 Comp Cams 7/16" Screw-in Rocker Arm Studs @ IRS $28.95 4808-8 Comp Cams Guideplates for hardened pushrods @ IRS $21.95 Crane/Comp Cams Stainless Steel Full Roller Rocker Arms - 1.6:1 --------------------------------------------------------------- Because of durability problems in street applications, LPE recommends stainless steel (SS) roller rockers over aluminum rockers. The best design we have found is the Comp Cams Hi-Tech stainless rockers that are available for SBC and BBC engines. Self-aligning rockers are a "drop-in" replacement for the stock rockers. These are available in 1.5 and 1.6 ratios and will allow the stock valve covers to be used without modification. However, they will not clear very large springs and they are only available with 3/8" rocker arm studs. This is not a problem for most smaller camshafts. But, if you are planning to run a very large camshaft or very big springs, you may be better off converting to a non-self-aligning valvetrain. The non-self aligning style rockers require guideplates and hardened pushrods. Non-self aligning rockers are machined to clear up to a 1.630" OD spring. Part numbers 40-11755-16 and 40-11752-16 rocker arms listed below (for example) are designed to be used with 7/16" rocker arm studs. The 7/16" stud will allow less flex in the valvetrain than the 3/8" stud, which will allow you to obtain maxium performance from your camshaft. This becomes more important as you put a larger cam in the engine. The use of non-self aligning rockers with guideplates is also a more fail-safe method of valvetrain alignment as compared to the self- aligning setup. Stock valvecovers will require minor modification with this setup. 1102-16 SS with 3/8" studs @ LPE $374.95 1302-16 4340 Pro Magnum Rockers with 3/8" studs @ IRS $259.99 1305-16 4340 Pro Magnum Rockers with 7/16" studs @ IRS $235.99 * Valve Lifters ------------- One of the most commonly overlooked areas of the valve train is the lifters. Poor quality lifters can adversely effect the usable RPM of your engine and even reduce oil pressure! LPE installs and recommends the following lifters for applications including hydraulic roller lifters. Comp Cams 850-16 or the new 875-16 (call how to adjust these) Comp Cams 853-16 SBC Hydrolic Roller Lifters $299.00 Value Lifter/Spring Seat & Open Settings ---------------------------------------- To run the HR lifters up to 6500 rpms Comp Cams suggests using very light parts and setting seat presure between 130-140 (130) and open presure between 300-350 (325). Setting up various lash adjustments, etc. is critical. Canton Competition Oil Pan @ IRS -------------------------------- Canton's LT1 Competition Road Race Oil Pan is a 7 1/2" deep fully baffled oil pan with a 5 Qt. capacity for a system capacity of 6 Qts. Designed for 93 and newer f-body's with LT1. 3 Trap Door Baffles Removeable One Way Screen Windage Tray Built-in Crank Scraper Oil Temp Fitting Magnetic Drain Plug 20mm Fitting For Low Oil Warning Sensor Works With Stock Starter 15-244T Oil pan $249.99 20-020 Oil pump pickup for high volume oil pump $36.99 383/396 ------- Standard 383 Stroker @ LPE -------------------------- Custom forged aluminum pistons - 11.0:1 compression ratio Custom forged steel crankshaft - 3.750" stroke Billet steel connecting rods - 5.850" length File fit plasma moly piston rings Computer balanced rotating assembly 58mm throttle body $Price unknown Shortblock Assemblies @ IRS --------------------------- Terminator Series shortblock assemblies are manufactured to the highest standards and include only the highest quality components. Shortblock assemblies are line honed, decked and squared, bored, torque plate honed and balanced to ensure long lasting performance. Shortblocks are then assembled with all new top quality components. NOTE - Ported heads not included? May come w/Terminator heads. Cola 4340 forged steel crankshaft Splayed 4 bolt main bearing caps Clevite 77 H-Series race bearings ARP fasteners Oliver 4340 forged steel rods SRP/JE forged pistons (CR?) Balanced rotating assembly Sealed Power plasma moly rings Melling high pressure oil pump Your choice of Comp Cams camshaft GM timing chain IRS383S $4799.00 (w/exchange) IRS396S $4799.00 (w/exchange)