Hello All! I have a challenger with a 360. My dash harness is out of a 73. I wanted to buy a new electronic distributer and I went ahead and bought the conversion kit because it comes with an ecu box and balast resister. I also bought an M+H engine harness that is stock for a 1973. The orange ECU box that came with the kit has 4 prongs. The original box has 5 prongs. The kit comes with a conntector to splice into your non electric ignition engine harness. My M+H harness is set up for electronic iginition. Here is my question. Will the 1973 engine harness work with the orange ECU box I got with the kit? I'm not sure what the effect is going to be missing the extra prong connector. I have attached a pic of the ECU I have. I am thinking I should have only bought the electronic distributor and bought the 4 prong balast resister and an original style ECU box.