Help with frozen track bar and shock nuts!

So tonight I set out to drain, clean, and fill the rear differential of my 99 Rodeo LS 4wd. Turns out that just wasn't meant to happen, not tonight anyway. I could not get the nut on the left side of the track bar to budge. Let's just say I went so far as to put a 3-ton floor jack under the end of my ratchet for "help". I ended up twisting the square nub right off the end of the ratchet. I loaded it up with liquid wrench, tapped it, let it sit, etc. with no results. All I can think of at this point is to use a nut splitter. If this is a good idea, does anybody know the part number for this nut?

The immobile nut on the track bar leads me to believe that the previous owner of my Rodeo never had the differential serviced. I just hit 84k miles today. I don't want to think about how bad this must be for my diffy.

Also, I have a sinking feeling that the nuts holding my shocks in will be similarly frozen and I'll have to split them too. I'm waiting for SensaTracs to be delivered. Anybody have part numbers on the shock mounting hardware since I'm betting it doesn't come with the new shocks?

Thanks,

Justin

Soaking it down with nut cracker is the first step.

Maybe an impact wrench?

Heat?