Will 17x9.5 and 17x11 wheels fit a 73 duster?
The front 17x9.5 will fit into the wheel well with a 6.125" backspace, and should clear the fender and frame with a 245/45/17. But the outer tie rod ends will probably hit the rim. I've seen as much as 6" backspace on a 17" rim without tie rod interference, but it depends on the design of the rim and some can only get away with ~5.6" backspace. You'll have to test fit it and see. If you only need an 1/8" spacer to clear the tie rod end the wheel will still fit. You can probably use up a 1/4" spacer and still clear the fender with a 245/45/17, but that will be about it.
The 17x11's with a 315 will not fit in the back without a 3" spring relocation and mini-tub. I have 18x10's with 295/35/18's on my '74 Duster, and it has a 1/2" hanger/shackle offset and a 1/2" trim on the quarter lip. There's no extra room to go any bigger, I have less than a 1/2" clearance to the quarters and the springs. As far as the backspace on the 11" rims, it should work with an A-body 8 3/4. It will not work with a B-body 8 3/4. That's what I run with my 18x10's and 295's, but I have a 7" backspace. With the 11" rim, a 6 7/8" backspace will put the wheels over an 1" further out than mine, and that means it would be outside of the quarters by over a 1/2", so that won't work unless you jack the back of the car up to 4wd height.
My car has 18x9's with a 35mm offset (6.4" backspace) and 275/35/18's up front, but I also have Dr. Diff's 13" brake kit, so that moves the track out so the effective backspace is more like 6.2". And the 18" rims allow more clearance for the tie rods than 17's, you can't run that much backspace with 17s. Out back I have 18x10s with 295/35/18's with a 38mm (7" backspace) with a 68-70 B-body rear, 1/2" spring offset, and an ~1/2" quarter lip trim. Everything clears, no rubbing, but no room to go bigger anywhere.
The front 17x9.5 will fit into the wheel well with a 6.125" backspace, and should clear the fender and frame with a 245/45/17. But the outer tie rod ends will probably hit the rim. I've seen as much as 6" backspace on a 17" rim without tie rod interference, but it depends on the design of the rim and some can only get away with ~5.6" backspace. You'll have to test fit it and see. If you only need an 1/8" spacer to clear the tie rod end the wheel will still fit. You can probably use up a 1/4" spacer and still clear the fender with a 245/45/17, but that will be about it.
The 17x11's with a 315 will not fit in the back without a 3" spring relocation and mini-tub. I have 18x10's with 295/35/18's on my '74 Duster, and it has a 1/2" hanger/shackle offset and a 1/2" trim on the quarter lip. There's no extra room to go any bigger, I have less than a 1/2" clearance to the quarters and the springs. As far as the backspace on the 11" rims, it should work with an A-body 8 3/4. It will not work with a B-body 8 3/4. That's what I run with my 18x10's and 295's, but I have a 7" backspace. With the 11" rim, a 6 7/8" backspace will put the wheels over an 1" further out than mine, and that means it would be outside of the quarters by over a 1/2", so that won't work unless you jack the back of the car up to 4wd height.
My car has 18x9's with a 35mm offset (6.4" backspace) and 275/35/18's up front, but I also have Dr. Diff's 13" brake kit, so that moves the track out so the effective backspace is more like 6.2". And the 18" rims allow more clearance for the tie rods than 17's, you can't run that much backspace with 17s. Out back I have 18x10s with 295/35/18's with a 38mm (7" backspace) with a 68-70 B-body rear, 1/2" spring offset, and an ~1/2" quarter lip trim. Everything clears, no rubbing, but no room to go bigger anywhere.
