Drivetrain swap/ wheelbase

Good info. My understanding is that the 8 3/4 and the 904 trans would have come factory in this barracuda and that the only difference would be the wheelbase which I would think would be the 3 inches you describe. If that's the case then I would need to use the shaft that is in the car now and and possibly shorten it? Not really any local shops that do this so im gonna have to ship it out or order online.