Re: What goes under the HEI module? (the, apparently, unanswerable que
It is ,or I should say was, since I can not find the part number for the thermal grease (Not Di-electric) from AC/Delco. I will have to call my buddies garage on Monday and see if any of the 20 oz. tube we had of the grease is still left over to get a part number off of it.
NAPA and Radio Shack sell non-silicone based thermal grease. The usual white stuff is silicone based (cheaper to buy) and it eventually spreads all over the inside of the distributor, which isn't good. The aftermarket tubes of white thermal paste uses for the thermal conducting part of the paste an oxide suspended in the gel, usually of Beryllium-Oxide, Zinc-Oxide or Silver-Oxide, or even Aluminum-Nitrate.
The paste has to be there or you will fry the module. If it died out from excess heat (usually from the motor not the transistors) then it has to be replaced. Also a common problem with white glove restorations is the paint on the intake manifold insulates the HEI from an electrical ground. The factory painted the motor, including the base of the distributor shaft and the exhaust manifold after it was assembled and tested under propane to verify it ran. There fore if you painted fifteen coats of hand rubbed lacquer and color sanded your intake you could cause the motor to stop working or given intermittent ignition problems due to a bad ground.