Quote:
Originally Posted by Sieg
Good system........as long as the rear differential is square in the car. 
The pinch weld is the most accurate reference on these cars and it's not exactly a fine line.  |
Not sure I'd trust the pinch weld Sieg, but your first point is key as a place to start. Measure the car twelve ways from Sunday and get that rear end centered as perfectly as possible. Then when placing the subframe underneath you get a reference point for a good X dimension from the front lower ball joints to a common reference point in the rear. If using rear shock mounts - or any other location on both sides such as axle tube ends - make sure they're square / centered as well!
The downside to this method is the the car may not be square to begin with, but it should track straight even if the body is a little off kilter.
There's more, but that's a good start.
EDIT: even after all that, I think mine was off by 3/16". Not sure if it was due to the subframe not being square (?), but that was as close as it would get.