Could be the position of the fan, or a fan that is too far from the radiator, lack of antifreeze. But there is one item you might check first. Check the timing. A retarded ignition setting can cause overheating. The bolt holding the octane selector plate may have come loose and you are anywhere between 1 and 10 degrees retarded. You probably want to be 2-6 degrees advanced with today's fuel, sometimes you can get away with a little more. So ideally you want the octane selector at 0 (center the 0 mark on the octane plate with the hash mark on the distributor pad), tighten down the bolt, and then set the timing to factory specs and see if that helps.
Last edited by Dragsix; 07/10/2020 1:44 PM.
