Correct. You need to adjust the pinion angle to exactly match the transmission. If you don't have adjustable upper or lower links, then get some. I'm assuming you have the canted 4 bar setup, like this:
Chris Alston's Chassisworks, Inc.; Chris Alston's Chassisworks, Inc. - Canted 4-Bar Rear System
edit - you can also get lower links that adjust both pinion angle and ride height.