I'm trying to get the correct EPR valve for my remanufactured RV-2 compressor to put on my 73 Charger 400, but I don't know which one to get. In the 73 parts catalog it shows two different numbers depending on different compressor part numbers but none of the compressor numbers match this remanufacutred one? The number cast into this compressor appears to be 1894397. It could be out of an earlier or later model car. I don't know where to look to cross compressor part numbers to applications.