Pair of electric fans with shroud if you are NOT going to tow. Engine Fan with clutch, Fan shroud and pusher electric fans IF you ARE going to tow. Did I mention the fan shroud?

SPAL and TriPac make the most powerful commercially available (to the general public) electric fans that I know of.

Scott

PS, did I mention the fan shroud

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me