Currently I've got a stock 401 in my CJ7 that runs hot at idle and/or low speed crawling around. I've got no inner fenders and a home-made cowl induction (open through the fire wall to the stock heater vent in front of the windshield). It has a 4 core radiator w/ one 12" flex-a-lite fan (w/ shroud ~1250 cfm) that runs at all times and one 10" no-name (no shroud ~850 cfm) on a manual switch. Between the two, almost all of the radiator core is covered. Because it runs nice and cool at speed I assume the radiator isn't the problem, but air flow is. I've found a dual 12" w/ shroud thats made for CJs and flows ~2500cfm, but I don't think its enough of an improvement to justify the $$$. Or a dual 13.5" at ~4500 cfm but i'm not sure I could make it fit and its really expensive. I was thinking of using a single high output 15" (perma-cool ~2950 cfm) and mounting it inside the stock mechanical fan shroud. I'm thinking the shroud will help move air through the whole radiator surface and the venturi effect will still be there. Do you think it will work? Any other great ideas?