lynn wrote:So now I think I understand more what you mean by parallel...I think what you mean is that I should splice into that hose the red arrow is pointing to and put the FPHE between the out from the water pump and the in of the thermostat?
Maybe. You need to find out how the flow goes in your engine, and where a cab heater would connect. A shop manual might tell. I can't tell from your pic. The water pump is usually hooked to the other side of the radiator.
I cut that hose, (it was very stuck) and found a 7/16"inch pipe...it is very rusty..problem? In the other photo is the outlet pipe I cast to go directly into the homemade FHPE then into the radiator. But now I suppose this hose will go directly from that outlet into the top of the radiator..right?
Yes if thats normally where the radiator goes.
I'm going to get some fresh eyes on this thing in case I've made some critical mistake I don't see....this has given me pause....
Good idea, you probably need someone who understands what parallel means.

