Weld subframe connectors loaded or unloaded?

IIRC, factory tolerance was +/- .125", so yes, pretty sloppy.

I think all of us would agree that flat and square clamped on a jig would be best. Flat to blueprint spec on multiple jackstands is a reasonable compromise. Putting them in on a car that's built, painted, and complete while sitting on the tires is probably going to work for most of us as well. Thats because most of us will notice the increase in rigidity more than we will notice if something is off by .125 of an inch.