Non-Rail / '61-'67Oldsmobile 260-455 c.i.d. V8 3/8" Studs / 1.6:1 Ratio Ultimate street Roller Rocker arm designed for Serious performance enthusiastsConstructed from 8620 chromemoly Steel, a superior material that will not flex and ensures maximum liftRoller tip reduces friction while stiff design and superior ratio accuracy yield more effective valve liftFor Applications with less than 350 lbs. of open spring pressureAlso Available in Kits:AMC 290-401 c.i.d. V8 Rockers and PushrodsOldsmobile 350-403 c.i.d. V8 Rockers, Pushrods, Studs and Guide PlatesOldsmobile 455 c.i.d. V8 Rockers, Pushrods, Studs and Guide Plates