Kelvinski, your cut n' paste is hard to read but thanks for the reminder. Thanks for the correction. I read that information last year and simply remembered wrongly. It comes with age. I forgot so my above statements are poo poo. An outer alternator case is not inside the generator case. The parts inside are special made to fit inside a stock appearance generator case.
I shamelessly borrowed a picture of an engine (attached). It's not mine. My statements below are "suppositions" and only concern our old Chevrolet/GMC trucks. Anyone reading this will have to make up their own minds.
The stock generator is below the exhaust manifold that is a terrible heat generator. It's also behind the radiator where hot air is pulled through the coils into the face of the generator. The generator air flow is aided by the small front pulley fan through the body and via small openings in the rear.
A normal size alternator has a larger diameter with more openings for cooling. It's not as long as a generator so it's mass is farther away from the exhaust manifold.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
