after fighting this overheating problem for three months I think I have it figured out. I have a rebuilt 327/300 hp in a 66 hardtop with air conditioning,powerglide.original front suspention.New HD radiator from chevy 2 only.High flow water pump.160 thermostat.duel 11 inch elec. fan. from spal.Car still gets hot (220)on 95 degree days with air on.I removed the hood and drove the car with air on and the temp.stays at 175-180. So I think I need to vent the hot air out of the engine compartment.I am thinking about a cowl induction hood ,but I don't know much about how they work.Anyone have any other ideas on venting the engine compartment.