FACTORY FLAW??!! need front bumper help...

[GMCPaul]

I can only think of 2 things then for your problem, support shifted to far to passenger side or tweaked frame in front where core support mounts. Have you tried loosening the front core support mounting bolts and shifting the entire front clip the opposite direction yet, you will need to do a front to rear hood adjustment at the same time as it will tighten the gap at the rear on the side you shift the clip? This may require a little different shimming in a few locations at the rear but most likely its the support was installed to far towards the passenger side. This is why Good Restoration shops charge the money they do because its not simply a matter of bolting parts as there is so much leeway that you can slide this or that piece when installing plus the factor of installing shims and everything else. Its like when you hit something and damage your grille and fender but not the core support and you get new pieces and go to put them on and you find the fender to door gap to tight, so now in order to install them you need to loosen the core support on that side and shift it forward.
So if you have pushed bumper as far towards drivers side as possible with the bolts at first just snugged but not fully tightened then I would have to assume my first thoughts a shifted support.