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PARTS INTENDED FOR COMPETITION USE ONLY.
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SMALL-BLOCK ENGINE INTAKE VALVES

Chevrolet Performance Small-Block 2.000 Inch Intake Valve With 11/32 Inch Stem Part No. 12363757

10241743

Valve Size: 1.940˝
Stem Size: 11/32˝

Stock replacement valve used in all of our crate engines except CT350/400, Fast Burn 385, and ZZ383/425

12555331

Valve Size: 2.000˝
Stem Size: 11/32˝

Stock replacement valve used in the 1996 LT4 engine, in our CT400, Fast Burn 385, and ZZ383/425, and in LT4 and Fast Burn heads

12363757

Valve Size: 2.000˝
Stem Size: 11/32˝

Stainless-steel valves with undercut stems to improve airflow, single-groove design, chrome-plated stems to reduce wear, and hardened tips to withstand high loads

SMALL-BLOCK EXHAUST VALVES

Chevrolet Performance Small-Block 1.940 Inch Intake Valve With 11/32 Inch Stem Part No. 10241743

12550909

Valve Size: 1.500˝
Stem Size: 11/32˝

Stock replacement valve used in all of our crate engines except CT350/400, Fast Burn 385, and ZZ383/425

12551313

Valve Size: 1.550˝
Stem Size: 11/32˝

Stock replacement valve used in the 1996 LT4 engine; in our CT400, Fast Burn 385, and ZZ383/425; and in LT4 and Fast Burn heads

SMALL-BLOCK VALVE SPRINGS

94666580

SINGLE WITH DAMPER

Outside Diameter: 1.241˝
Pressure at Installed Height: 80 lbs. @ 1.700˝
Solid Height: 1.150˝
Average Weight (lbs @ in): 267

Retainer Part Number: 14003715
Valve Seal Kit: 10132715
Production spring for 350-/290-HP engines

10134358

SINGLE WITH DAMPER

Outside Diameter: 1.273˝
Pressure at Installed Height: 110 lbs. @ 1.700˝
Solid Height: 1.160˝
Average Weight (lbs @ in): 356

Retainer Part Number: 14003974
Valve Seal Kit: 10132715
Chrome silicone steel; use with aluminum heads P/N 12556463; orange color code

330585

DUAL

Outside Diameter: 1.379˝
Pressure at Installed Height: 140 lbs. @ 1.750˝
Solid Height: 1.150˝

Average Weight (lbs @ in): 325
Valve Seal Kit: 10132715
Use with cam P/N 3927140 and all moderate-lift racing cams

10206040

SINGLE SPRING

Outside Diameter: 1.300˝
Pressure at Installed Height: 85 lbs. @1.780˝
Solid Height: 1.260˝
Average Weight (lbs @ in): 373

Retainer Part Number: 10168424
Valve Seal Kit: N/A
1992–1993 LT1 production Corvette engine

12625033

SINGLE SPRING

Outside Diameter: 1.320˝
Pressure at Installed Height: 101 lbs. @1.780˝
Solid Height: 1.220˝
Average Weight (lbs @ in): 332

Retainer Part Number: 19301708
Valve Seal Kit: N/A
CT400, ZZ5, and ZZ383 engines (Beehive Spring)

12499224

SPRING KIT

Outside Diameter: 1.320˝
Pressure at Installed Height: 101 lbs. @1.780˝
Solid Height: 1.220˝
Average Weight (lbs @ in): 332

Retainer Part Number: 19301708
Valve Seal Kit: N/A
Kit of 16 springs P/N 12625033 (Beehive Spring)

10212811

SINGLE SPRING

Outside Diameter: 1.250˝
Pressure at Installed Height: 80 lbs. @1.700˝
Solid Height: 1.200˝
Average Weight (lbs @ in): 256

Retainer Part Number: 10241744
Valve Seal Kit: N/A
CT350/350, 350 HO engines

19154761

SPRING KIT

Outside Diameter: 1.250˝
Pressure at Installed Height: 80# lbs. @1.700˝
Solid Height: 1.200˝
Average Weight (lbs @ in): 256

Retainer Part Number: 10241744
Valve Seal Kit: N/A
Kit of 16 Springs P/N 10212811

19300952

BEEHIVE SPRING CONVERSION KIT

Convert the valvetrain on your aluminum Fast Burn heads to the beehive-type system used on Chevrolet Performance’s latest Fast Burn heads (P/N 19300955) — and used on the SP350, ZZ5, ZZ6, SP383, and ZZ383 crate engines and the CT400 — to gain greater high-rpm capability and valvetrain stability. The springs, retainers, and other hardware are direct replacements for the conventional springs and hardware, with no machining of the valve spring seat required. The engine’s existing intake and exhaust valves are retained, allowing installation without cylinder head removal if compressed air or another method is used to hold the valves closed. The engine’s existing rocker arms are also retained. The kit comes with components to convert a pair of cylinder heads, including:

16 Springs
16 Caps

16 Seats
16 Keepers

NOTE: The conversion kit is intended only for Fast Burn heads and is not compatible with Vortec heads because of insufficient room for the spring seats.

SMALL-BLOCK VALVE SPRING COMPONENTS

10212809

LT4 VALVE SPRING SHIM

Lightweight shims as used on 1996 LT4 Corvette special LT service heads P/N 12363287 and Fast Burn heads

Use with spring P/N 12551483

10185066

SPRING SHIM

Used on ZZ3-series 350 HO engines

Spacer is 1.350" O.D. x 0.561" I.D. x .050" thick

3875916

SPRING SHIM

55/64" I.D. x 1-31/64" O.D. x 0.015" thick

10212810

VALVE STEM SEAL

Used on LT4 and ZZ4 heads as well as Chevrolet Performance Parts head assemblies P/N 25534421, 25534431, 12363287, and 12464298

12511890

VALVE STEM SEAL KIT

Late-model V-8 seal kit for 11/32" diameter valve stems

Includes eight intake seals, eight exhaust seals, and 16 oil stem seals

NOTE: Check for seal-to-guide interference with high-lift cams.

10241744

VALVE SPRING RETAINER

Used on 350 HP, 350 Ram Jet, and HT383

10045007

VALVE SPRING RETAINER

For all ZZ3 series engines

NOTE: When converting ZZZ, ZZ1 or ZZ2 engines to ZZ3 series cap, valve spring shield must be removed and add cap P/N 10045007, seal P/N 460483, and spacer P/N 10185066