FREE SHIPPING ON MOST CRATE ENGINES

GM BIG-BLOCK VALVES

Part Number Valve Size Stem Size Description Intake Valves
14097045 2.19" 3/8" Stock replacement valve for Gen V & VI 454 and 502 HO engines
12366986 2.19" 11/32" Stainless steel valve with undercut chrome plated stems, single groove design, hardened tips, used on ZZ454
12366987 2.25" 11/32" Stainless steel valve with undercut chrome plated stems, single groove design, hardened tips, used on ZZ502 and ZZ572

Exhaust Valves
14097049 1.88" 3/8" Stock replacement valve for Gen V & VI 454 and 502 HO engines
12366988 1.88" 11/32" Stainless steel valve with undercut chrome plated stems, single groove design, hardened tips, used on ZZ454
88963128 1.88" 11/32" Stainless steel valve with undercut chrome plated stems, single groove design, hardened tips, used on ZZ502 and ZZ572

GM BIG-BLOCK VALVE SPRINGS

Part Description Outside Pressure at Solid Average Retainer Valve Technical Number Diameter Installed Height Height Rate Part Seal Kit Notes (lbs per in) Number
3970627 Dual 1.487" 105# @ 1.88" 1.28" 267 3964264 460527 For high-performance 396/427/454 LS6 engines
12371061 Dual Kit 1.487" 105# @ 1.88" 1.28" 267 3964264 460527 Kit of 16 P/N 3970627 springs
3989354 Dual 1.538" 128# @ 1.90" 1.26" 356 3989353 Aftermarket Use with cam P/N 3994094 w/damper PC-type seal
12371062 Dual w/ 1.538" 128# @ 1.90" 1.26" 356 3989353 Aftermarket Kit of 16 P/N 3989354 springs damper kit PC-type seal
14097002 Dual 1.487" 110# @ 1.88" 1.37" 316 14096274 12550422 Use with 454 and 502 HO engines
12495514 Dual Kit 1.487" 110# @ 1.88" 1.37" 316 14096274 12550422 Kit of 16 P/N 14097002 springs
12462970 Dual 1.514" 140# @ 1.94" 1.20" 325 12366990 12495690 Use with 502/502 hp engines Spring
12495691 Dual 1.514" 140# @ 1.94" 1.20" 325 12366990 12495690 Kit of 16 P/N 12462970 springs Spring Kit
88963934 Dual 1.540" 197# @ 1.80" N/A N/A 12366990 88963936 Use with 572/620 hp engines Spring
88963933 Dual 1.567" 205# @ 2.30" N/A N/A 12366990 88963936 Use with 572/720 hp engines Spring
366282 Dual 1.525" 128# @ 1.70" 1.26" 406 366254 Aftermarket For competition engines Spring PC-type seal

GM VALVE SPRING COMPONENTS

387591 Spring Shim • 55/64" I.D. x 1 31/64" O.D. x 0.015" thick 3731058 Spring Shim • 55/64" I.D. x 1-15/16" O.D. x 0.030" thick 3891521 Spring Shim • 55/64" I.D. x 1 31/64" O.D. x 0.065" thick 88963937 Spring Shim • Shim for all 572 engines 88963935 Valve Spring Locator • Valve spring locator for setting the valve spring in the right location on all 572 engines 12360874 Retainer/Seal Kit • Kit of 16 retainers P/N 12550421 and 16 seals P/N 12550422 for 1991-and-newer Gen V and VI engines • New design improves oil economy • The valve guide bosses require minor machining with high-lift cams 12495688 Valve Spring Cap Kit • Kit of 16 special machined steel performance valve spring caps P/N 12366990 for use with spring P/N 12462970 on 502 and 572 engines 3964264 Valve Spring Retainer • Retainer and seal for valve spring P/N 3970627 3989353 Valve Spring Retainer • Steel retainer for valve spring P/N 3989354 12550421 Valve Spring Retainer • For 1991-and-newer Gen V and VI engines 3947880 Valve Spring Key • Hardened steel split locks for production and racing engines • Color-coded purple • Sold individually. Order 32 per engine. 12366992 Valve Spring Cap Lock • For 502 and 572 engines with aluminum heads 460527 Valve Stem Seal • Umbrella-type team seal for all big-block engines 12550422 Valve Stem Seal • Seal for 1991-and-newer Gen V and VI engines • Use with valve spring P/N 12550421 • The valve guide boss must be machined slightly for seal to retainer clearance when using high-lift cams 12495690 Valve Spring Stem Seal Kit • Kit of 16 special high-performance seals for the 502 engine kit • Use with spring kit P/N 12495691 88963936 Valve Spring Seal• Use with all 572 engines