11. Troutman chose Comp’s new Ultra Pro Magnum steel rocker arms for their excellent combination of strength with light weight. (Works for us, especially since it’s his motor, we’re just borrowing it.) Different ratios are used to get the valve movement Troutman wants—1.7:1 for the intakes and 1.65 for the exhausts. The tall poly-locks are for fitting up a rocker stud girdle later on.