With a 1.430" Outer Diameter, a recommended installed height of 1.750" and a seat pressure of 132 pounds, the 986 springs are ideal for use in Chevrolet Small Blocks, Ford Windsors and Ford Small Blocks with retro-fit hydraulic roller cams. Features a max lift of 0.540", and is compatible with our 740-16 retainers, 4704-16 locators and 4754 shims.