Trunion Tool - GM LS Rocker Arms

The COMP CAMS Trunion Tool for GM LS Rocker Arms is a specialized installation tool designed for technicians and engine builders working with LS-series small-block engines. This precision tool eliminates guesswork and potential damage when installing rocker arm components, making it essential for anyone performing valve train work on Gen III, IV, or V LS platforms. Whether you're rebuilding a stock 5.3L or assembling a high-performance 427, this tool ensures proper rocker arm alignment and seating without marring critical fastener surfaces.

The trunion tool works by providing a controlled installation interface that guides the rocker arm shaft through the mounting bracket with precision. COMP CAMS engineers this tool to match OEM specifications, preventing cross-threading and ensuring the rocker arm seats flush against the cylinder head. The compact 2.8 x 2 x 4.1 inch design delivers professional-grade functionality at a fraction of shop tool costs, making it ideal for both home garage builders and commercial machine shops managing multiple LS builds simultaneously.

This tool is critical for anyone installing aftermarket rocker arms, upgrading factory components, or rebuilding a complete LS valve train. Compatibility extends across all LS-family engines—from truck 5.3L and 6.0L platforms to big-block derivatives and specialty crate engines. At 0.6 lbs, the tool is portable enough for field service or mobile engine work, yet durable enough for repeated daily use in high-volume performance shops. Purchase this rocker arm installation tool today to eliminate valve train installation headaches and ensure proper seating on every LS engine project.