Fits 350 Chevy! These high silicon alloy flat-top pistons are an outstanding value and are ideal for street, bracket and circle track ''claimers''. Compression ratio are 9.35:1 with 64cc heads and 8.34:1 with 76cc heads. 4.00'' bore hypereutectic pistons are available in +.030, .040 and .060. Ring grooves are 5/64'', 5/64'', 3/16''. 1/pkg.