COMP Cams 19001-8 Ultra-Gold Aluminum Roller Rocker Arm with 1.5 Ratio and 3/8" Stud Diameter for Small Block Chevrolet, (Set of 8) For small block chevy applications with 3/8 inch studs, 1.5 ratio Designed for high performance street and race engines Precision-sorted trunion bearings withstand elevated valve spring pressure and valve lift Additional clearance, up to 1.650 inch O.D. valve spring