Well I am close to welding the spring perches on the axle tubes. I did a search to find the pinion agle, I did not see a hard and fast #. If i measure the pinion angle on my old rear end, is that a safe bet? It might sound like a silly question, but I only want to do this once. I am planning on using an angle gauge on the spring perches in conjunction with a level on the open face of the differential, then transfer those measurements to the new rear end. I am also planning on using the superstock springs with the new axle, will that make any difference? Thanks for any replies.