The perches are wider? My 80 was a direct bolt in. The springs lined up exactly with the D80 welded on perches. When I drilled the holes for the sway bar they also lined up exactly with the frame. I did use the oem D80 u-bolt plates also instead of trying to use the old plates that only fit the 3.5" D70 axle.

 

Yeah, the springs, perches, Ubolts are spaced at 2.5" on the old axle. The 80 has 3" wide perches and spring plate holes. I was originally going to just run them at the 3" width, but the concern is the gap between the ubolt and the springs. Would it be bad to have 1/4" of space between them since they are still clamping down?