Rear shackle clearance problem

Ok so I need some help making a decision here. First let me start that I have searched but everything is talking about shackle angle associated with lifts. I just picked up a 93 xj 2wd to use as my DD. Got it cheap because it was rear-ended before. Already checked it out and no major damage just bumper, hatch, and gas tank. The problem I'm running into is the rear shackles, both have beautiful 45* angles. The passenger side has plenty of clearance to move but the drivers side only has about 1/4" of clearance before it hits the back of the shackle box. I was thinking about just cutting out the area that it will hit and being done with it but that would cut out some of the back of the shackle box as well as 1 bolt for that side of the bumper mount. I've looked at HD offroad's kit but it give's 1.5" lift which I just want to keep this one stock but will do that as a last resort. Can anybody think of a way to take care of this or is that the best/only two options?

How does the driver's side have less clearance than the passenger side? Did somebody knock off the weld nut for the rear bumper bracket on the passenger side but not the driver's side? I had an issue with my boomerang shackles hitting these weldnuts but got rid of the weldnuts in short order...

No when it was rear ended the damage was more on the drivers than passenger side. The driver side of the gas tank is dented in and the frame rail from the axle back to the rear cross member has a couple of wrinkles in it but no cracks. So it's the rear crossmember that the bumper bolts to broke the little welded tab on the frame rail and moved towards the shackle by about 1/2" or so. I know HD offroads bracket relocation setup would fix it but wanted to see if there was any other options before going that route.

Oh well I wasn't aware that your unibody was tweaked. You could probably cut away the crossmember directly behind the shackle like you mentioned and not have any adverse effects.