What should the pinion angle be on a 14bolt ff? I have an 83 k5 with a 400/205, 6" lift springs both front and rear. The rear springs came with a 6* shim but driveshaft is binding or hitting the u-joint. I measured and came up with 9* up. After axle wrap I should move it up 6-7*. Does this seem right? Just want to make sure before. Thanks.