3431665 is a variable speed wiper for a '73 Barracuda, Challenger, Charger, Coronet, or Satellite. It will work fine if the four wires are in the 1970 position on the bulkhead connector. On a '70 variable speed E-body bulkhead connector, when looking at the wires when they are plugged into the car, the brown is upper left, red lower left and the two greens are on the right ( the side of the plug with the funny shape). The wire positions on a '73 wiper motor plug might be different and so you may have to move the wires on the plug to make it work on the '70. Good luck
