GM Engine Mount Small Clamshell

The GM Engine Mount Small Clamshell from PROTHANE is a polyurethane motor mount insert engineered to replace worn OEM rubber mounts on General Motors vehicles from 1973 to 1993. As a mechanic, you know that degraded engine mounts allow excessive engine rock and vibration transfer to the frame and drivetrain—a condition that accelerates wear on transmission mounts, suspension bushings, and engine bay hardware. This small clamshell insert addresses that problem by providing a stiffer, more durable elastomer replacement that maintains proper engine geometry while reducing parasitic motion during acceleration, deceleration, and cornering.

PROTHANE's polyurethane formulation offers superior resistance to heat, oil, ozone, and UV degradation compared to factory rubber compounds, extending service life well beyond OEM specifications. The small clamshell design fits into the existing mount cavity without requiring bracket modification, making installation straightforward for shops and enthusiasts alike. Polyurethane is firmer than rubber, which means engine movement is noticeably reduced under load—this translates to tighter shift feel, reduced clunk during gear changes, and improved throttle response consistency. The black color indicates UV-stabilized material, critical for under-hood longevity in vehicles that see regular use or performance driving.

This mount insert is ideal for owners of classic and vintage GM engine platforms—Chevrolet small-block, big-block, and Buick V8 applications across the 1973–1993 window—who want to restore precise drivetrain feel without a full engine-out rebuild. Street rods, restorations, and daily drivers all benefit from the improved stability and reduced vibration this polyurethane insert provides. Installation requires engine support and careful clamshell positioning to ensure proper seating; most installations complete in under an hour with basic hand tools. Verify your specific engine and mount location before ordering, as clamshell orientation varies by application. Weighing just 3.5 lbs and compact in dimension, it ships easily and integrates seamlessly into any engine mount refresh project.