new cross shaft install on 69

[lowlyfec10]

i ordered new moog lower shafts to rebuild the LCAs while i had them disconnected to mess with my springs. having trouble tightening the caps and keeping the shaft centered. and if i thread the caps down seperately (no shaft) they arent exactly flush when bottomed out against the arm. done some searching and found one guys thread where he clamped the shaft and turned the caps 1 even turn at a time together but has anyone had any issues with the caps not going in straight?