Trunion Kit - GM LS-Type Rocker Arm Retro-Fit

The Trunion Kit - GM LS-Type Rocker Arm Retro-Fit by COMP CAMS is an engineered bearing upgrade designed for enthusiasts and engine builders who demand improved reliability and durability in LS-series engine rocker arm assemblies. This retrofit kit addresses the limitations of stock rocker arm bearing geometry by introducing modern trunnion technology, which distributes loads more effectively across the rocker pivot point. Built for street performance, racing, and high-rev applications, this kit extends component lifespan while reducing friction-related wear that can compromise valve train integrity over extended use.

The trunnion bearing design replaces the traditional rocker arm pivot with a precision ball-bearing assembly that maintains consistent clearance under dynamic load conditions. This upgrade reduces side-loading stresses that develop during high-RPM operation and fuel-heavy tuning scenarios, where stock geometry often permits unwanted wear patterns. The retrofit maintains full compatibility with existing GM LS-series cylinder head architecture, eliminating the need for costly machine work or head replacement. COMP CAMS engineers this kit to OEM dimensional standards, ensuring proper engagement with factory mounting surfaces while delivering the precision bearing performance found in purpose-built race engines.

This kit is ideal for LS engine builders working on LS1, LS2, LS3, and other variants within the GM LS family who are planning head reconditioning, valve train upgrades, or high-performance builds. Installers should plan for professional machine shop setup or advanced DIY experience, as proper trunnion alignment and preload are critical to performance. The compact kit design (measuring 6.4 x 2.7 x 11.9 inches, weighing 4.02 lbs) ships complete with all necessary components for a full rocker arm bearing retrofit, making it an economical alternative to full rocker arm replacement for engines targeting 500+ horsepower outputs or extended track duty.