Does a crossover instead of a circulating pump really give you more hp? What effect does it have on the cooling of the engine if any? This will be on a whippled 454 mag. Thanks..Winkman

it doesn't give more. just uses less, so more is left over for the prop. many people have mentioned overheat issues and higher temp in back of engine issues. usually have to drill out rear water passage cover on back of intake and plumb water outlets there. i don't think many people recommend it as a way to save 10 or so hp.

You need to do a search, there are a ton of discussions over this topic. If you have a good seawater pump with good flow through your block, you will see virtually no difference with a crossover verses a circulation pump. Provided you are using a crossover with a bypass. I am using a crossover and I measure my water temps at the front and back of my heads and there is about 5 degrees difference. I would recommend using a crossover that has an offset on the inlet, mine is centered and the right bank runs about 10 to 15 degrees cooler than the left.