That still puts the rim right at the lip of the wheelwell. Mount a tire and you're slicin' rubber.
Even 6" of backspacing on a 7" wheel only gives you 1/2" clearance on each side according to your measurements- and that's before you add the thickness of the wheel lip (a 7' wide wheel is closer to 7 1/2" wide). The sidewall of a mounted tire will protrude more than that. Plus you need to accommodate sidewall flex when cornering... I think you're looking at 6" rims, but I don't know if you can get enough offset on a 6". Those adapters are killing you here.
Now this is all based on your measurements- 8" of wheelwell clearance, lip to leaf. 1 1/2 to lip, 6 1/2 to the leaf from the adapter face. Double check your measurements, because I know guys run 7" wide rims on early As all the time- but I think those adapters are going to limit your ability to find rims with enough backspace.