mini tub
A '70 Duster should have close to 15" from the frame rail to the quarter lip, if it hasn't been trimmed/rolled already. So even allowing a 1/2" of clearance on the frame and quarter lip on a car with an untrimmed quarter you'd have close to 14" to work with for the section width of the tire.
The 3" relocation really makes a lot of space. 72BBswingers car had a 3" relocation and mini tub, he had 18x12's with 335/30/18's on it and said he still had some space. This is his car (was I guess, he sold it). But this is a Dart, and with nothing else changed a Duster will have an extra 1" of wheel tub space than a Dart does because of the wider quarters. So, 335's would be a piece of cake. Maybe 355's?
Backspace will be dependent on whether or not the axles have been upgraded to BBP or not and what rear brakes you're running. But a 12" wide rim should be easy. And that's without any trimming or rolling of the quarter. On my Duster, with a rolled flat quarter lip and quarter that was pushed out with the fender lip roller, I've got 16.5" from quarter to the outside of the frame rail.
A '70 Duster should have close to 15" from the frame rail to the quarter lip, if it hasn't been trimmed/rolled already. So even allowing a 1/2" of clearance on the frame and quarter lip on a car with an untrimmed quarter you'd have close to 14" to work with for the section width of the tire.
The 3" relocation really makes a lot of space. 72BBswingers car had a 3" relocation and mini tub, he had 18x12's with 335/30/18's on it and said he still had some space. This is his car (was I guess, he sold it). But this is a Dart, and with nothing else changed a Duster will have an extra 1" of wheel tub space than a Dart does because of the wider quarters. So, 335's would be a piece of cake. Maybe 355's?
Backspace will be dependent on whether or not the axles have been upgraded to BBP or not and what rear brakes you're running. But a 12" wide rim should be easy. And that's without any trimming or rolling of the quarter. On my Duster, with a rolled flat quarter lip and quarter that was pushed out with the fender lip roller, I've got 16.5" from quarter to the outside of the frame rail.