i have a 89 cherokee with a 87 corvette motor. Recently i blew my ron davis rad because it over heated. So i made it home. I just put a stock jeep rad in. Buttoned it up. It still over heats and i have no heat in the cab. It takes a mile and its hitting red. I changed the thermostat 3000miles ago. The heater core is clear and flushed. So what the hell do i do next?