I just found the original ECU from a 76 Charger I parted out. The Charger was a 360 2-barrel car. The ECU is a 5 pin and looks exactly like the original unit from my Challenger. The only difference is the part number on the housing. Can I assume that the 73 part number was just superseded and this ECU is OK to use on my 318?
None of the aftermarked units look the same. I can clean this one up and repaint it. Thanks