It depends- if you have stock bushings or MM control arms then you can tighten them up with the car in the air. If you have control arms that have poly bushings on BOTH ends, then you need to have the car with the suspension loaded or else you will get binding, as they poly bushings do not articulate as much.
This is good info! Thank you. I was able to get the stock upper control arms in today, was much easier then last time. Wont be getting the MM control arms though til friday. Now the waiting game :X