Utilizing years of valvetrain design experience, the latest FEA stress analysis technology, and an exhaustive testing regiment (dyno and Spintron), the COMP Cams engineering team left no detail to chance. Everything from casting techniques to valve spring clearance was scrutinized to ensure that the new Ultra Pro Magnum rocker arms not only lived up to the lofty standards of their predecessor, but also took stud mount rocker performance, stability, and value to a whole new level. The most noticeable advancement with the COMP Cams Ultra Pro Magnum rocker arms centers around their nearly unbreakable investment cast 8650 chromoly body. The arched, web-like design delivers a nearly 29 percent increase in strength and rigidity, while reducing the moment of inertia and optimizing the dynamic balance. The resulting rockers maximize lift and valvetrain control at high rpm. The increased retainer and valve spring clearances of the new design enable the use of large-diameter valve springs, retainers, and locks, without clearance or fitment issues. The new black oxide exterior finish offers a distinctive appearance, along with long-term corrosion resistance. The COMP Cams Ultra Pro Magnum rocker arms feature an oversized trunnion and precision-sorted needle bearings designed for use with high-load valve springs. Additionally, these unique rockers also feature hardened roller tips for reduced friction and elimination of the valve stem "side loading" that causes premature valve guide wear. The COMP Cams Ultra Pro Magnum rocker arms feature a fully rebuildable design, which means that they very well may be the last rocker arms that you ever have to purchase.