My frame isn't square... shocking!

[jerimy75]

Hey guys - looking for some experience from others that have installed DMs before. I have a '72 SWB that I am adding PB's Mild DM front and rear. I have the front mocked up already and have moved to the back. I bought the weld in notches and am mocking them up to tack weld in place. I have two possible issues:

1. I've measured back the specified distance to place the notch CL (bump stop hole). Passenger side is pretty close if not dead on. With the bridge in but bolts loose, the driver's side is about 1/4" if not more forward of the specified CL. If I center the notch, I won't be able to get the bridge in. I don't have the axle in yet but am thinking if the trailing arms are the same length and the axle is centered in the frame and notch I should be good. Has anyone had this issue before? Am I on the right path?

2. Not sure it's an issue but want to confirm my thought process: Frame is not square, it's about 1/8" out measuring between cab mounts. My question is should I square up my notches (see issue 1 above) or mimic the frame 'out-of-squareness'?

I don't know the history of the truck and don't know if it was in any accidents. Any insight you guys can give will be greatly appreciated, thanks!