Ah, it must be the rear diff. I rebuilt them a week before and didn't tighten them enough, so when they slipped at the track, I tightened the rear diff almost all the way.
I did get rear ended at the beginning of the day but I don't think it's the camber links, they seem okay.
thanks for the help.
Jaybee-Buy a screw extractor set. There are ones on ebay for around $5. You could probably drill it out too but then you'll have to replace the bellcrank post thing.