Application: 302/351W ? 1978 and later with production heads. Cast iron and aluminum GT-40 heads. Ratio nMounting: 1.70:1 Bolt On. Valve Type: Inline. Notes: Same as "Cobra" 5.0L Mustang. These rocker arms have beefy trunnions for extra long life. Die cast aluminum construction. Reduces friction and horsepower loss. Increases high RPM valve train stability. High strength trunnion supported by needle roller bearings. Grade 8 adjusting nuts. Precision machined from 2024 high tensile strength aircraft alloy extrusions. NOTE: photos & specs may vary