I really wouldn't be comfortable with a pusher gasoline powered airboat. I feel it would almost certainly get hot. I know some of the glow guys rig up electric fans to help cool their pusher style airboats, and glow engines run much cooler than gasoline powered engines by their very nature.

The advice here is to run it as a tractor style to assure decent engine cooling and engine longevity, not to mention ease of tuning without overheating the engine.

If you go with water cooling to preserve your ability to run it as a pusher, I would run a dedicated water pump for the cooling system. With water cooling, you would have to run it only on water; not grass, ice, snow, etc. But with a dedicated water pump, at least you could just set the boat in the water and do your tuning, while the water pump provided cooling even though the boat wasnt moving.

Tractor is really the way to go for all around practicality.....

AV8TOR