I already have questions about the pinion angle, but that's another story. It has a 65/67 B body 8.75 that has the perches moved to 43" on center to fit which checks out but the pinion seems angled up a little excessively.
A and B bodies used different spring perch angles. If you kept the angle the same when you moved the perches you'll probably need to shim them to get the right angle. And a 2" lift spring will also change the pinion angle quite a bit.
With a 65-67 B-body rear you're going to need about 5.75" of backspace to clear 275's on a 15x8 if you put the car at stock ride height.
