The Ultra Pro Magnumâ„¢ Roller Rocker Arms for Chevy V8 265-400 Applications not only live up to the lofty standards of the original Pro Magnums but they also take Stud mount Rocker performance, stability and value to a whole new level. These Rocker arms feature a 3/8\" Stud diameter and 1.52 ratio. The 8650 chromemoly material and arched, web-like design deliver increased strength and rigidity while still reducing the moment of inertia and optimizing the dynamic balance. A unique black oxide exterior finish helps prevent corrosion and increases durability. Featuring Oversized trunnions, precision-sorted needle bearings and hardened Roller tips for the ultimate in performance and dependability. Optimized retainer and valve spring clearances allow for use of most diameter springs, retainers and +.050\" locks without clearance or fitment issues.

• Investment cast 8650 chromemoly body and arched, web-like design deliver increased strength and rigidity while still reducing the moment of inertia. Unique black oxide exterior finish helps prevent corrosion and increases durability.
• Optimized retainer and valve spring clearances allow for use of most diameter springs, retainers and +.050\" locks without clearance or fitment issues.
• Feature Oversized trunnions, precision-sorted needle bearings and hardened Roller tips.
• Lifetime Warranty - So strong that we guarantee the Rocker bodies against breakage for life. For use with up to 850 lbs of open spring pressure.