When do I tighten the pivot shaft nuts on my truck's suspension?

[72timemachine]

I just got done cleaning and painting all my front suspension parts (engine sub-frame, control arms, etc) and I cannot find any information on when to tighten the lower pivot shaft nuts on the truck.

I found a very good video on Youtube where this guy was rebuilding the front end of an older Chevelle and he said to tighten the control arm bushings when the full weight of the car was on the ground. Granted my suspension is a bit different but should I do the same thing and wait until my truck is on the ground? My other concern is, that if that is true, I would imagine I should also wait until I get the engine and transmission installed to get the full weight of the vehicle on the ground.

Thanks for any help.