I have a 37 Buick Special with a 52 263ci straight eight engine and a Vintage Air heat/cool unit. The a/c will give you frost bite but will throw out heat for only about 15 seconds. I parked my Ranger pickup beside the Buick and ran long heater hoses from the Ranger to the Buick and heater worked fine. Has to be the water pump but it keeps the engine cool with the a/c running on 100* days. Have run a wire in the heater hose nipple on the w-p and feel no blockage. With either hose disconnected and engine running it flows coolant but with almost zero pressure. Can stop flow by capping hose with thumb and exerting almost no pressure. I don't want to hear "water pump" because it's a pure bitch to change out with the near zero radiator clearance so hoping for other suggestions. Thank you.