We couldn't help but try out Comp's latest line of innovative rocker arms. Ultra-Pro Magnums are cast 8650 chromoly bodies and have hardened roller tips. The new weblike design delivers nearly a 29-percent increase in strength and rigidity. They also feature an oversized trunion and precision-sorted needle bearings for use with high-load valvesprings. Even better, they're rebuildable and come with a lifetime guarantee.