[mike16]

I replaced my fixed pitch 4 bladed fan. about 14 inches in diameter with one from a 76 pontiac grand prix, 7 blades, 19 inches in diameter and a new thermal clutch. my new(er) fan sits perfectly in the shroud opening with the front half of the blades inside the shroud and the back half of the blades ouside the shroud. never had an overheating problem to begin with But I sure dont now either.