I'm running 17x8 front and 17x9.5 rear on a '70 Challenger. It has no suspension narrowing but I have trimmed the rear fender lips and it has "rolled" type factory fenders on the front. BS is 4 1/8" front and 5 1/2" rear. Done again, the rear would be 5 1/4" BS.

Tires are 265/17/40 rear and 235/17/45 front. These sizes give no "rub" as tested under extreme conditions with TB's removed and also on the road. Many folks have run wider with either some rub or sheetmetal modifications.

Done again, I'd probably go with 18's to get ultra high performance Z rated tires in ~26-27" diameter. With 17's they are in the 25" range.