What you need to look for is the vent tube attachment on the side of the filler tube, but I'm not sure the two flanges are the same. Why not either modify or have someone modify yours? Request a photo here of a non EVAP Duster/ Demon filler and then mimic that. You can look up and find a diagram in the service manuals, but the ones I've seen are Dart/ Valiant which are physically a bit different---they however might give you idea
Basic:
Because of the tube fitting, the non-Evap tube goes in from the inside of the trunk, with the tube flange on the inside, AKA you cannot push the tube in with the vent fitting sticking out ---into the hole in the quarter, from the outside of the car.
This meas you need to weld/ braze something like a pipe bushing into your old tube "flush enough" that it will slide in. Maybe just SLIGHTLY notch the quarter panel for clearance. And, you want the fitting far enough down into the tube that it will not interfere with a nozzle insertion.
Above sugessted OldManMopar. That guys knows everything. He's worked on, restored, rebuilt Mopars since he was a kid. He may just have one you need.
