Ok...finally! I got my shackles replaced. I used a grinder to fix the end of the bolt I screwed up, and heating them up with a torch gun and pounding the craaaaap out of it seemed to be the only effective way (besides cutting).

To start off with, I cut the exhaust pipe back past the shackles so the bolt would come off on the pass. side. I took the top bolts out first and loosened up the U-bolts to let the leafs go down further to give me more clearance while beating on the bottom bolt.

We heated the bottom bolt and whaled on it with a fairly large hammer and large nail set (just watch your hand, I have hammer head imprints on mine ). Eventually it came out. We repeated the process on the pass. side. The whole thing took us about 3 1/2 hours.

 

A tip for the future.... When beating on a bolt to get it out, put the nut on a few turns and hit that. It'll save you a lot of headaches dealing with mushroomed bolts.

 

USE AN AIR HAMMER to get the bolts out!!!!! Literally took me 5 to 10 minutes to get both of the shackles off. I couldn't get mine to budge either and I was using a pretty big steel mallet to pound away with. The mallet and WD-40 did nothing for me. The air hammer is the only way to go IMO.