If you used a motorcycle radiator as your primary heat exchanger, you would just need to have it at the highest point while filling it or add a spot to "burp" the system if you mounted it low.

 

Duner, do you happen to know how high the heater core is relative to the inlet and outlets on the fire wall? Just wondering since I would like to keep my small radiator mounted the highest as you say.
Thanks, Tim.

 

Hmmm, I have no clue about where it would be on your truck. My guess is that it would be right behind the inlet and outlets on the other side of the fire wall. The design of the heater core will just be basically a long tube, so there's really no where for any air bubbles to stop once you turn the pump on. I don't think you'll need to worry about burping the heater core once the system is moving water.

 

hmm, sounds interesting and promising........how about those pics and maybe a schematic?

 

Yes,very interesting