Set of (8) +.010 over size Hypereutectic flat top pistons & matching rings compatible with 1997-2004 GM 5.7L LS1 V-8 engines with press-fit pins. These are for blocks bored +.010 over or 3.905" Bore diameter. Head Type: Flat top with no valve reliefs. Piston Material: Hyper eutectic aluminum. Compression Height: 1.330 in. Wrist Pin Style: Press-fit. Wrist Pin Diameter: .945 in.; pins included. NOTE: Please confirm Pin .945" diameter. Some later models have pin diameter of .943".