Before Pro Magnum Roller Rocker Arms were introduced by Comp Cams, the choice for competition rocker arms was stainless steel for its strength and reliability or aluminum for its light weight and cost.
Now you get the best of both worlds...

Unsurpassed Strength
Pro Magnum Roller Rockers are made of 8650 chromemoly steel, which is approximately three times stronger than 7075-T6 (the aluminum typically used for rocker arms).

Less weight where it counts
Engineers/Pros at Comp Cams used advanced computer technology, including Finite Element Analysis, to refine Pro Magnum Roller Rockers. Strength was added where needed to reduce mass in low stress areas, resulting in 5% less weight at the valve than most aluminum rockers. What this means to you: greater RPM and valvetrain stability.

Superior design = Superior performance
The unique design of Pro Magnum Rockers enables the use of a larger trunion with more needle bearings, which spreads the load more evenly so the rocker lasts longer. Another important feature is an integral pushrod seat to ensure accuracy and save weight. The design also provides plenty of clearance for most high-performance valve springs.