Mopar Head Gasket Tech

Recently I stopped by to talk with Steve Carlson, another local Mopar guy. He had the top end pulled off the 440 in his ’69 Road Runner.

I learned that the thicker composite FelPro gasket head gaskets lower the compression a half point over the original style steel shim head gaskets.

Every B/RB engine built since its inception in 1958 came with steel shim head gaskets regardless of compression ratio,whether it be high compression or low compression.

Of course, factory steel gaskets pale in comparison to a performance steel gasket. There are differences, with various vendors offerings single layer, multi layer, various compression rings, plus aftermarket steel shim gaskets aid high compression engines in not blowing.

Steve suggests spraying both sides with copper gasket coat before installation of any steel shim head gasket, the silver paint doesn’t work as well.

Also of note is the Mopar Performance steel shim head gaskets varied in installed thickness. Early ones measured .020, but the later ones in the last few years measure .016.

Something to think about if the heads have been off your big Chrysler since it has left the factory.