I recently purchased a 1993 GMC 2500 Rally Wagon with a 350 engine. The heater core had been bipassed due to a leak prior to my purchase. I have now replaced the heater core. I need a diagram telling me which hose should be contected to which port of the heater control valve as the bipass had preformed prior to my purchase of the vehicle. Unfortunately the repair manual that I have is worthless. Thanks for your help.