question on adjustable uppers

question on adjustable uppersNEED HELP

I am puttin in a set of adjustable upper control arms on a 92 lx, I have a noticable vibration in the rear , rear is completely new 3.73's,bearings clutch pacs shims everything. but vibration still exsists, had aluminum driveshaft recheck and its not bent or out of round, I was told it was the pinion angle. Question is ..how hard is it to get the 4 degrees needed for center pivoting, do I make the adjustables shorter than the stock control arms or longer to swing the yoke upwards towards the floor?? I am doing this monday so any help would be greatly appreciated thanks. Do I have to use a magnetic protractor or will measuring off the bottom of the driveshaft on a loaded chassis be sufficient?