Cylinder Sleeve GM LS 3.985 Bore

The Cylinder Sleeve GM LS 3.985 Bore is a critical component for engine builders looking to reinforce or repair high-performance GM LS-series blocks. Designed for those pushing the limits of horsepower and torque, this modular integrated deck sleeve provides a robust solution for blocks that have suffered bore damage or require increased structural integrity. By replacing the factory cylinder walls, users can ensure their engine block can withstand the extreme internal pressures common in forced induction or high-compression racing applications.

Engineered with a 3.985-inch bore and a 5.800-inch height, this sleeve features a dual flat design to facilitate precise fitment within the engine block architecture. The 0.170-inch wall thickness and 4.325-inch outer diameter are machined from high-strength steel to provide superior heat dissipation and wear resistance compared to standard factory liners. This specific Darton Sleeves model utilizes the Modular Integrated Deck technology to create a solid deck surface, significantly reducing cylinder movement and head gasket failure during high-stress operation.

Professional engine shops and performance enthusiasts will find this sleeve essential for custom LS builds where bore consistency and block rigidity are non-negotiable. It is specifically designed for GM LS-series engines, offering a reliable path to restoring a block to factory specifications or preparing it for competitive track use. When reviewing specifications or looking to buy a replacement liner, this dual flat steel sleeve offers the precision required for a seamless installation and long-term durability in demanding automotive environments.