i have some new perchs to weld up on the axle to compensate for any rotation and to recenter the axle up.
I see how new perches would allow you to rotate the pinion up, but how do you plan to "recenter the axle" with new perches? You should center your axle with the front spring hanger.
The shackle angle, I believe, should be about 30* from vertical to allow good compression and droop. If you have it at vertical, you limit droop and might even allow it to go the other way and get stuck that way. Say goodbye to your springs if that happens. They'll probably get all jacked up. Too far from vertical and you limit compression travel cuz it'll bottom out on the frame.
You should move the front hanger forward about 4~5" from eye to eye and the rear shackle hanger probably needs to be moved back. Unless you're running these backwards. That's a whole 'nother cup o' tea! Haha!