About rear axle. You can take any A body 8.75 rear end and get couple of any other body axle ( but A body ), remove the axle hubs from them and reinstall them on the A body axles from the full assembly rear end you got. I think that's way easier than mod a full rear end dimmensions.
This job has being done here with success even on 1/4 miles cars.
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
