I have a lot of hot air coming in under my feet from the fire wall I assume. I havent really looked to see whats causing it, but what type of things should I be looking for, and whats the best way to plug it. The ac has been removed and I have an M20 engine, so Im sure the guy that did the conversion removed something??

theres a chance your heater water valve is stuck open, its a little valve that opens when you turn the heater dial on and allows water from the radiator and engine to flow into the heater core. so if it was stuck on hot water would always be flowing into the heater core causing the air coming through your vents to be hot. i just thought of this cause my heater valve broke a little while ago and spilled radiator fluid everywhere.