BTR rocker arm trunnion upgrade kits improve your stock LS Series rocker arms with captured needle-style roller bearings. They'll provide more stability for your modified application. BTR upgrade kits include rocker arm bearings, trunnions, snap rings, and assembly washers. Replace weak stock LS components with BTR rocker arm trunnion upgrades to support your added power. Order the kit recommended for your year/make and engine application.