Pinion Angle in and of itself is not very important, you need to also consider, engine/transmission angle, resulting driveshaft angle and planned usage (i.e. are you at the track with a ton of power or what).
I relocated my lower arm attach points and did a T56 with my relocated arms, I also changed out my spring perches and I spent a lot of time researching and aligning my pinion and transmission to get within some reasonable driveline angles.
I probably over did it but I have no vibration issues. Now if I could just figure out why this clutch fork over extends...
'95 B4U LT1/T56 in Purple Pearl. 24x 355 with I believe most of the bolt-ons.
'63 C10 LT1/4L60E from B-Body. Rides like a Cadillac thanks to air bags.
'06 GTO LS2/T56 Torrid Red with CAI and Borla Cat-back thanks to the lady who rear ended me.
Still in Wichita.