This listing is for a box of brand new high performance valve spring shims made by Silver Seal/VSI. Box includes 48-50 shims that are .060" thick.

They are the high performance version shims that are designed to better stand up to stiffer valve spring pressures than the stock style shims. Please measure the spring pocket and valve guide diameter on your heads to ensure the correct size you need before ordering.

This set fits many of the following big block Chevy V8 engines and also many of the following Oldsmobile V8 engines that GM used in some Buick, Cadillac, Chevy, GMC, Oldsmobile and Pontiac vehicles:

Chevy Engines:

• 396 CID (6.5L) 1966-1970
• 402 CID (6.6L) 1970-1972
• 427 CID (7.0L) 1966-1969
• 454 CID (7.4L) 1970-2000

Oldsmobile Engines:

• 260 CID (4.3L) 1975-1982 Gas
• 260 CID (4.3L) 1979-1980 Diesel
• 307 CID (5.0L) 1980-1990
• 330 CID (5.4L) 1964-1967
• 350 CID (5.7L) 1968-1980 Gas
• 350 CID (5.7L) 1978-1985 Diesel
• 371 CID (6.1L) 1957-1960
• 394 CID (6.5L) 1959-1964
• 400 CID (6.6L) 1965-1969
• 403 CID (6.6L) 1977-1979
• 425 CID (7.0L) 1965-1967
• 455 CID (7.5L) 1968-1976

Shim Details/Specifications:

• Part Number: A303HP
• Shim Thickness: 0.060"
• Shim Outside Diameter: 1.480"
• Shim Inside Diameter: 0.700"

Please check your old parts to ensure the correct fit, refer to the manufacturers catalog or contact me with any application questions.