A-Body differences

Hello everyone

Since the Duster, demon, dart sport, and barracuda have a wheelbase of 108" and a Dart has a wheelbase of 111" I was wondering what parts were longer in the unibody of the dart.

I'm looking at a 69 Dart Swinger 340 that is pretty rough under the hood as far as one frame rail and inner fender aprons, I am thinking of drilling all the spotwelds that hold the front subframe, inner fender aprons to the fire wall and main body of the car and completely replacing it with the same pieces from another car, I might have access to a 72 duster. I'm wondering if the front unibody frame and all the inner fenders are all the same on these two models..

Thanks
Any help would be appreciated, I want to bring this beautiful car back from the dead.

Brambles