Decrease friction and increase longevity when directly compared to flat tappet lifters Custom Car Shop Engines & Components Components Car Engine Lifters Hydraulic Roller Hydraulic Roller Lifters Competition Cams 850-16 Hydraulic Roller Lifters for Small Block Chevy 305 and 350c.i. Engines Originally Equipped with Hydraulic Roller Cam, 1987-Present, Including LT1 and LS Series, Camshafts & Parts - Canada LS7 : Lifters, guide trays, Made in USA | Elgin Industries | Engine and... Hydraulic roller lifters can handle much more aggressive cam profiles than flat tappets unlocking performance potential., 842 diameter 122g weight 2 , 66 seat height Comp Cams Replacement Hydraulic Roller Lifters COMP Cams Hydraulic Roller Lifters are a performance upgrade for stock hydraulic roller lifters or retro-fit hydraulic roller lifters for non-roller blocks.