@Jim Kueneman , hope all is well. can you give me a pic or explanation of what you did for your heater return line? The magnum is a bit tricky with only one 3/8 port and the others being 1/8. Thanks!
I’m not sure what you are asking. The one was from the water pump and the other I used a big block nipple in the manifold. They were the correct size for the heater core.