Well, from what I've seen here, and from the posts that I've read, the OP doesn't really have much of a problem. If these are 5/8-18 bolts grade 5 bolts and they are truly rated for 128 ft/Ibs and 130 ft/Ibs is not too much, then torque to that value.

If not, then I've only got one other suggestion and that is to use a different castle nut on the same bolt to see if that will grab from a different position and lock in at about 100 Ft/Ibs. Bolts and nuts can be subject to stress and maybe one of the 2 has been subject to more stress than the other.

The only reason I weighed in is because I experienced the same problem with my set up going from power front drums to power front discs. I ended up resolving it by trying a different castle nut after ensuring that everything was clean and straight.