Since no one has replied yet, I went out and crawled under our '94 to see if I could figure out where you're at.
You're talking about the massive bolts and nuts that attach the inner side of the control arm to the frame flanges, right?
It looks like you're the victim on the wrong side of a tolerance spec. You've probably already thought of this, but can you reverse the bolt and bring it through from the inside rather than from the outside?
Can you shave the bolt down a bit in length (leaving the nut on, and then drawing it off after cutting)?
Any chance of levering the gas tank away from your acces area (maybe it'* slipped backwards a bit with age?).
Don't know if any of this will help, but maybe you'll be inspired to keep trying (or else one of the gearguys will have a method).