Texas Airboat Association

Have a dixie, 1985 air boat, radiator is below motor, I put a chevy 350 in it, and it's over heating, does anyone know what is wrong. It has a good radiator and there is no air pockets in water. Need help, Thanks Hank

I'm sure you checked all the obvious, pump suction hose to bottom radiator, top hose from intake/thermostat housing to top of radiator, does it have a thermostat, what size? What kind of set-up on radiator cap, where is it? Are you running expansion tank? Overflow tank?
How hot is hot? Does it heat up quickly or gradually? When I built my big block, thought I same problem, but ended up being location of sending unit was all. Where's yours? Should be in water jacket on intake by thermostat.