1970 Duster, Trans-Am-inspired "Pro Touring" build

MopaR&D said
No worries, happy to answer. I got some guidance from @72bluNblu on front tire size, they fit like gloves lol. No rubbing at all. I do have a touch of rubbing in the rear on the fenders with the 18x9" standard-offset Mustang wheels and 275/40ZR-18 Continentals even after folding over the inner fender lips (read: smacking with a 2-lb sledge lol). Note I swapped a 1967 B-body 8 3/4" into my car as well. Tires are pretty close (<1/2") to the rear leaves as well so that's about the max width that will fit in the rear on a Duster/Demon/Dart Sport.

From my experience previously running 215/65-15 in the front, those actually did rub just a hair on the fenders at full lock. Tire diameter seems to be the limiting factor on these A-bodies more so than width. Also going with 18s as opposed to 17s give extra clearance to the upper ball joints and allow more wheel width towards the center of the car.

Thanks!

I really want to run a 275/35R18 all the way around, but am struggling to find a wheel that works and doesn't cost an arm and a leg. And even with the right offset, sounds like a 275 takes a little work. Not opposed to messing with it, just easier if I don't have to.

If I am honest with myself, the rear has to have a 275 (or bigger) tire, the current 245 just looks too small proportionally back there (IMO), but the front would probably be fine with a 245/40R18 or the 255/40R18 you are running. And if they fit on a 18x9 +24mm wheel, that costs half what I am seeing for an 18x9 +35mm wheel, all the better.

Besides, part of the reason I want to run a square setup is so I can rotate the tires. But there is a good probability that the rear wheel will end up with a different offset which pretty much negates the idea anyway.