Plugs & Fittings Kit LT/ LS Cooling Manifold

The Plugs & Fittings Kit LT/LS Cooling Manifold by Holley (MPN 97-177) is a precision component engineered for builders and mechanics upgrading LS and LT platform cooling systems. This kit addresses a critical gap in modern engine swaps and cooling system customization, where stock manifold ports require sealing and proper fluid routing through aftermarket cooling components. Whether you're performing an LS swap into a vintage chassis, upgrading cooling capacity on a high-horsepower build, or transitioning to a custom radiator setup, this plugs and fittings assembly ensures leak-free operation and correct coolant flow management.

Holley's plugs and fittings kit provides OEM-quality sealing solutions and threaded ports that integrate seamlessly with LS and LT cooling manifolds. The kit includes precision-machined plugs that block unused ports—a critical detail when adapting manifolds to non-factory cooling configurations—and compatible fittings that mate with standard hose barbs and adapters used in modern cooling systems. Compact at 2.5 x 2.5 x 2.5 inches and weighing just 0.62 lbs, this kit fits easily in any toolbox and won't add measurable weight to your engine bay. The threaded fittings accept standard -AN or coolant line adapters, making integration with custom radiator hose routing straightforward for both street and race applications.

This kit is essential for anyone running an LT or LS engine platform in a modified cooling setup, from mild street engines to high-output turbocharged or supercharged builds. Professional installers, engine builders, and DIY enthusiasts benefit from having Holley's factory-engineered components on hand during cooling system assembly, eliminating improvised solutions that risk coolant leaks or air pockets. Proper port sealing with matched fittings ensures stable coolant temperatures and protects against system failures under sustained boost or extended track use. Install this kit as part of your cooling manifold preparation, and gain confidence that every connection point is engineered for your specific LT or LS platform.