The rear end was narrowed 3", I believe, on each side. I can't tell you the flange to flange right now, but if I get the wheels off in the future, I'll try to measure it. I'm putting in a 4 speed in a couple weeks. ;)
It is a 15x10 w/ 4.5 backspacing. I wanted to go to 3.5" bs but didn't think I'd have the room. I'm glad I stayed w/ the 4.5. They fit nicely.
There is plenty of room to lower the car a little more. I have one more adjustment hole to go to on the front brackets to lower the rear of the car. The pinion angle will be checked again after that.