Upper control arm bolts spinning. 66 C10

[grubsster]

Hi all, I was hoping someone could help me with this issue. I recently did some work on the front end of my truck and now need an alignment. When I got to the shop the upper control arm mount bolts spin in the frame mounts preventing adjustment. I understand these are splined bolts and was wondering if anyone else has dealt with this issue and what would be the best course of action.

Thanks in advance...