COMP Cams Hustler Short Travel Hydraulic Roller Lifters GM 603/604 - Set of 16Hustler Lifters feature reduced internal piston travel for increased stiffness and greater valve lift when compared to stocklifters in Sealed GM 603 and 604 crate and 1987 1998 GM small block engines. The short travel design also increases responsiveness, allowing for quicker recovery from any valve float or bad harmonics in the valve train. Catalog User 1