Unleaded gas can ruin a head in 500 miles if it is not set up to run it. Unleaded gas burns hotter and thus more completely than leaded gas. This is good for the atmosphere but rough on cylinder heads. This additional heat cooks the valves and seats almost to melting point and the softened metal can no longer stand up to the pounding. Slowly the valves bash their seats up into the head, destroying it. The solution is to replace the exhaust valves with ones made of a harder material, to put hardened seats in place of the stock ones that are simply cut into the head material and replace the guides with bronze to absorb the heat better.

Bulletproof your valve train with our Head Update Kit! This kit comes with everything you need to update your head to run unleaded gas. We have made it easy for you. Just buy this kit and your machine shop will do the rest. This kit can be purchased by itself or included with either the Major Engine Kit or the Minor Engine Kit.



HUD001 1963 – 71 $255.95
HUD002 1972 – 80 $245.95
HUD003 63-71 Added to Major Engine Kit $175.95
HUD004 72-80 Added to Major Engine Kit $175.95