Fits Gen III/IV & Gen V - GM Performance LS7 style hydraulic roller lifters are designed as direct replacements for your engine. These lifters (similar to GM #12499225) were designed for use by GM to be used in high performance engine builds and incorporate improved valving to allow higher rpm capability. Non-link blade design, precision ground internal piston that is graded and matched to the body's inside diameter to deliver a slow leak down for minimal loss in lift and duration at high rpm. Includes 16 hydraulic roller lifters in the set. Also fits SBC & LT1 engines.