The valvetrain is measured and test-fitted before final assembly. Jesel's rocker-arm kit for the Big Chief uses three different stands and rockers: two for the intakes; one for the exhaust. Both the "dog-leg" and "Z" intake rocker-arm configurations use a 1.7:1 ratio, but have different offsets to reach around the large intake ports. A 1.75:1 ratio is used over on the exhaust side. Three different-length Manton pushrods are also used to attain optimum rocker-arm geometry.