Setting pinion angle question

[jlay]

Have my ridetech 4 link installed and i want to finish the installation by setting the pinion angle and welding the upper bar brackets to the rear. My question is does it matter what set of rims and tires that are on the car and does the car need to be at "full weight"? What I mean is that the car is basically a shell and I am going to put the sub under it to get the angle i need. Is this ok or do i need more weight to get it at a lower ride height?