Reply to "Edelbrock heads"

Aluminum heads on an iron block are always a risk. You must make sure that you use the Felpro "blue" teflon coated head gaskets.

These are especially made for this application. They in fact float between the head and the block since the aluminum and iron expand at different rates, the head gasket cannot be "glued" to either.

The torque of the bolts is critical to this since only a prescribed amount of torque will work. It is in fact possible to put too much torque to the head bolts and thus prevent the head gasket to float properly. This in essence makes the head gasket "wrinkle" in order to move and creates in most cases a dribble of coolant leak. Sound familiar?

Also, I have found that when you make this swap to aluminum heads that it is important to install new head bolts, and torque them in three stages, in the pattern prescribed in the shop manual. DON'T OVER TORQUE THEM.

Until gaskets like the Felpro came along it was next to impossible to keep these combinations from leaking.