83 CJ7 with a LT1 out of a 97 Z28. Engine has 50,000 miles on it. It has a be cool radiator and one of the best electric fans you can buy. It moves a ton of air. Went offroading in Tellico is weekend and the damn think kept overheating. I know its not a air moving problem, we took the hood off and the engine actually ran hotter at that point. Already put a new water pump on and tried some of that water wetter stuff. I'm out of ideas here. The radiator is made for this application, what else could it be?!? Could the engine be running lean thus creating more heat?