Where do the heater hoses connect to?

[PbFut]

What year? I don't know about early years but my 72 AC truck has a valve that turns off the water to the heater core when AC is on. It otherwise is open to allow for flow to assist in avoiding cylinder head hot spots during warm up. The supply hose goes from the intake manifold to the valve mounted on the wheel well, to the core and then return from core to the radiator. You need the AC vacuum lines in working order for the valve to correctly function. I had to trace my lines to locate spits at the dash HVAC control. Once repaired all worked great.