Upper Control Arm Shaft - HELP

[ChumBucket]

OK guys, so I spent about 2 hours today trying to figure out the correct assembly of the upper control arm. I've removed the upper control arms as part of my renovation and now I'm trying to get them back together and having some questions/issues, hopefully y'all can help me out.

'69 1/2 ton 2wd (Sorry no pics)

1) When a place the shaft b/w the UCA holes, do I try to center the shaft from right to left? If so, how the h%#^ do you do that? Does it matter as long as the big end caps are threaded enough and have enough bearing on the hole?

2) What's the deal with those little rubber dust/grease seals? Do they go b/w the UCA mounting hole and the shaft (in other words, are they a bearing surface)? Or do they just do their best to keep the grease in the threaded area?

Any help/advice would be great...any possible links describing this issue would be great to. THANKS!