Let's say the cooling system is ok.

What could be happening inside the engine that makes it such a high BTU water heater???
I'm just curious, I have seen in the past some engines just make a lot more heat than others and I've always thought that it has more to do with tuneing and the Cam setup ( when the obvious issues are addressed and taken care of like intake leaks and stuck stats, poor or missing shrouds etc. ) these things can answer a lot of questions and save the OP time and money.

Common sense, the least common of all the senses.
Mom.

For fear of ridicule, society stifles creativity.
Ricky Valdes