Made from high grade chrome-moly steel, lighter and three times stronger than aluminum rocker arms. Trunion, valve tip roller and shaft made from chrome-moly steel. Design allows clearance for most high performance valve springs.
Extra large trunions for better load distribution and wear. Maximum open spring pressure 800 pounds. Laser etched with Engine Pro logo. EPR Chevy SBC Roller Rocker Arm 1.6 Ratio Chrome-Moly Steel 7/16" Stud These fit Small Block Chevy 283 305 350 400 engines They will mount on a 7/16" diameter stud and are 1.6 ratio.