This listing is for a set of eight (8)+.040" 3.935" bore size cast aluminum pistons and a cast piston ring set (Hastings/Perfect Circle/MAHLE) compatible replacements for 1957-67 Chevrolet models with the 283 cid V-8 engine; except fuel injection. P/N (8) 235NP+50076CP. Piston specifications are as follows: BORE: 3.935" (at .060" Over Bore) HEAD TYPE: Flat head w/4-valve reliefs RING LANDS: 5/64"-5/64"-3/16" COMP. DISTANCE: 1.780" PIN DIAMETER: .927"