tclederman - yes on the extra pump fittings - in my big bus project I'm using the core from a passenger area heater of a TF schoolie as part of my hydronic heat setup, and it was plumbed that way - a huge core too [maybe 10x20], in relation to the normal cab heaters in our trucks, so obviously no problem with the pump handling the distance or extra volume of water
what I plan for the project panel is a core about the size of the one under the dash inset into the double lower sidewall behind the driver seat, T-eed off the existing lines
Bill