I cannot seem to locate any information on the proper method of plumbing in my fine vintage heater/defroster unit to my Highboy's '48 Ford Flathead engine. I believe the lower heater (intake) water tube connects by flex hose to one of the threaded ports in the RH aluminum head. Am I correct? I do not know where the upper heater (return) water tube connects into the cooling system. Recommendations, Please. Also, can anyone tell me which direction the coolant water flows through this engine?