1972 Duster Build with my Daughter

Thanks for the details! The problem is measuring super heat is not really accurate. The only tap I have for getting the low side pressure is all the way back at the compressor in the head of one of the pistons. I would have no idea how to handle going through the muffler then through the ports where the EPR valve use be then into the head low side chamber.

The pressure drop probably isn't too bad. I'm surprised that you don't have a Schrader port on the suction manifold where it bolts to the compressor body? You must be using a line set from a non-EPR vehicle?

I'd get the best measurements that you can. A slightly inaccurate measurement is better than no measurements at all.