Do you have the original radiator and a "zero pressure" cooling system? It's possible you've got the radiator over filled. There should be a couple of inches at least of free space below the radiator cap for expansion. If you're not having to add coolant frequently, it's not likely you've got an actual "overheat" problem. The short shaft pump puts the fan too low on the radiator for good cooling at idle speed or in traffic.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!