If you spend all the money and time on a Alterkion front end for handling reasons, I'd sure as hell would get something bigger than a 225 wide tire to give the rest of those upgrades the most grip possible.
5.72 backspacing shouldn't be an issue with an alterkion. It's an issue with stock spindles, and really a problem with the dropped spindles.
Forget the pissing around, what can you do in the rear to fit 275/40/17's in a 72 Dart to match 275/40/17's in the front!