Gaskets

Diesel Head Gaskets for Powerstroke, Cummins & Duramax
Head gasket failure on a diesel truck is rarely about the gasket itself — it’s about cylinder pressure overcoming the clamping force holding the head to the block. The right gasket strategy depends on the engine, the application, and whether the head has been upgraded. Using a stock gasket on an O-ringed head, or the wrong thickness on a machined block, turns a repair into a repeat job.

We stock MLS head gaskets, fire ring gaskets, solid seal kits, oversized gaskets for decked or machined blocks, and complete head gasket sets for Powerstroke 6.0L, 6.4L, 6.7L; Cummins 5.9L 12-valve, 24-valve, Common Rail, and 6.7L; and Duramax 6.6L.

Which gasket is right for your engine?
Standard MLS gaskets are the correct choice for most stock and mildly modified diesel engines. Multi-layer steel construction provides reliable sealing across heat cycles on engines with a flat, properly prepared deck surface.

Fire ring gaskets add a steel sealing ring around each combustion bore for increased clamping pressure at the most critical sealing point. Used on performance builds, compound turbo setups, and engines running elevated boost where standard MLS gaskets have failed.

Solid seal kits combine a high-spec gasket with matched hardware for a complete upper-end sealing solution. Designed for Cummins and Duramax platforms where the factory sealing setup is a known weak point under load.

Oversized gaskets (+.010, +.020) are required when the block or head deck has been machined past factory spec. Running a standard-thickness gasket on a machined surface creates a compression ratio and sealing geometry problem — match the gasket thickness to the machine work.

Always use MLS gaskets with O-ringed heads. Composite gaskets are not compatible with O-ringed sealing surfaces. If your head has machined O-rings, a multi-layer steel gasket is mandatory.

Questions about gasket selection for your specific build? Call 512-355-2999 before you order.