Okay so, after 2/4 leaf bolts being stuck, I'm over it. I'm wanting to just cut it all out with an angle grinder/cutting blade. I realize that if I cut the front leaf bolts out, part of it will be stuck inside of the bracket, when that happens, would an air hammer be sufficient to knock the remaining part of the bolt/the weld nut out?

heat it up with a torch and grab a breaker bar

Alright, so just heat it up and pry on it and that should bust the weld nut weld?

Its should allow you to get the bolts all the way out, replace with all new Grade 8 hardware

Youre going to need to cut the bottom of the box (where the welded nut is) open to get that out and put in a new one. Its REALLY not as hard as some people make it out to be.

Couple ??? about this ^^^. Is the replacement nut OEM simular? Self centering? Is the hole at bottom patched or left open, or does it matter?
Thanks!!

I've had to do this to both sides, its easy so long as you have an angle grinder. Cut a hole in the pocket, air hammer popped my old weld nuts off no problem. Buy new grade 8 hardware. Don't remember the exact size but I do remember they are 120mm long by maybe 15mm diameter. Search forum for exact bolt size, its there somewhere. Buy matching nut and washers. Use nut and washer inside leaf pocket mount thingamajig.

Oh, I also just left my pockets open.