Looking to go from Rallye 14X6 to Cragar SS - 1973 Dart Sport 340
In my opinion, get enough backspacing to keep the tires tucked in will be important. I tried some aftermarket 6" wide wheels 40 years ago on my Dart Sport and the tires were under the wheel opening. I mean the fender would sit right down on top of the outside edge of the tread.
I ended up using chrome rimmed Rallye wheels with painted centers.
This is the only picture I have with those wheels. 8" rears with L60 Goodyear Polyglas GT and 6" front with F70 Goodyear Polyglas GT.