The Ultra Pro Magnum Roller Rocker Arms not only live up to the lofty standards of the original Pro Magnum Rockers, but they also take stud mount rocker performance, stability and value to a whole new level. The modern arched, web-like design delivers increased strength and rigidity while still reducing the moment of inertia and optimizing the dynamic balance. * Investment cast 8650 chromemoly body and arched, weblike design deliver increased strength and rigidity while reducing moment of inertia * Withstand valve spring pressures up to 850 lbs. * Unique black oxide exterior finish helps prevent corrosion, thus increasing durability * Increased retainer and valve spring clearances allow use of large diameter springs, retainers and +.050" locks without clearance or fitment issues * Feature oversized trunnions, precision-sorted needle bearings and hardened roller tips PartNumber : cca1678-16 Description : Ultra Pro Magnum Rocker Arm; 16 Pieces Title : 1678-16 Rocker Arms, GM LS3 1.8 Bolt Down Rocker Arm Ratio : 1.8 Rocker Arm Series : Ultra Pro Magnum Rocker Stud Diameter : Pedestal Mount California Proposition 65 : WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov Engine Family : LS3 (Factory Offset) Maximum Valve Spring Open Pressure : 850 Rocker Arm Material : 8650 Chromemoly Steel Ratio : 1.8 Stud Diameter : Pedestal Mount Engine Components::Rocker Arms