Chris, what rear end and brake package are you going to run? SSBC, IIRC for the brakes? My '68 Dart has 255/40/18's on the back. They rub on the outer trim a little because my rear end isn't centered due to factory tolerances. If I roll the fenders, it should be perfect, but I'm also going to be adding Dr Diff's leaf spring offset kit which should also gain me an extra 3/4". As for me, I used an A-body 8 3/4 with LBP axles, and Dr Diff's 11.75" disk brake kit. The wheels I used have an effective offset of +17mm and are 18 x 9's. Once you get the rear end in the car measure the distance from the face of your rotor to the inner trim of your fender and also to your leaf springs. Depending on your tire size, that will tell you what wheel you need to go with. I even made a cardboard cut-out wheel to reduce the chances of interference.