Help me confirm my measurements and back spacing thought

autoxcuda said
I thought later dusters had more room than the earlier darts. That 70 Dart does not have the room as my 2nd gen Barracuda.

?I thought 73-76 duster/dart sport's have more room inside than earlier barracudas and darts?

Are your tubs untouched in your Duster? Outer lip rolled?

They do, all of the Dusters/Demons/Dart Sports have about an inch more room than any of the Darts/Scamps/Valiants. Barracuda's are close to the same as the sport body cars in the rear, there's about an extra inch compared to the Darts. But the extra inch is in the outer wheelhouse, so only the measurement to the quarter is different. The inner wheelhouses, framerails and spring locations are the same on all of the 67-76 A-bodies. Some of the 67-69 Darts seem to run a little tighter for clearance, but again it's all to the quarters, all the inner measurements are the same. My '71 Dart has 12" from the inner wheelhouse to the quarter flange, which is within an 1/8" of the OP. So pretty darn close considering what we're measuring. My Duster had 13" inner wheelhouse to quarter flange before I started cutting.

On my Duster the quarter flange is cut back to the spot welds with the outer wheel house, which added roughly a 1/2" of clearance on my car. And I have a 1/2" spring offset to get 295's in there, but the wheelhouses are untouched. So for determining the clearance on the springs and inner wheelhouse I can still use the measurements from my Duster, both the OP and I are using an offset spring kit. Just can't use the outer measurements because I've got 13.5" of wheelhouse to work with now. I actually get pretty similar spring to wheel mount measurements on my Duster if I correct for the B-body rear axle. My car as it sits with the 68-70 B-body 8 3/4 has 8" from the springs to the wheel mount, and the B body rear axle is about 1.15" wider per side than the A-body 8 3/4 with BBP axles. So that would put my distance at 6.85" compared to the OP's 7". An 1/8" could easily be a measurement error or just factory tolerances. I know I'm using a tape measure and a square for those measurements so they're not perfect.