I recently purchased a 1976 Cadillac Coupe DeVille with the 500 cubic inch engine. It has an overheating problem that I've been unable to solve. I have pulled the heads and replaced the gaskets and did a valve job at the same time. It has a new water pump, radiator (aluminum aftermarket), 180 degree thermostat, and all new hoses and belts yet it still overheats after driving 10 miles. I'm having a new heavy duty four row brass/copper radiator built for it. I talked to Jerry at Cadillac Only and he told me that the car came factory equipped with a two piece fan shroud. The bottom shroud is attached to the radiator core frame. My car doesn't have that. I also learned that the car should have a radiator fan with a clutch. I don't have that either. I would like someone to email (ernest.walker5442@sbcglobal.net) me some pictures of what the shroud looks like. I would also appreciate any comments anyone would care to submit on this situation. Help!! I'm trying to rescue this old Caddy.

 

Actually most of the issue occurred in the DeVille is overheating,these are very old made cars so with the passage of time,not an issue spend dome dollar on its engine and carborator and it get solve and it gives you a comfortable drive.

 

Have you checked the timing?