If you ordered the rearend directly from Strange, the spring perch to pinion angle will not be correct for a "stock" A-body. Unless you specified otherwise, Strange installs the default perch/pinion angle at 7 degrees positive, which is correct for an E-body but 2 degrees farther up when installed in an A-body.
To further compound the problem, because you installed a T-56 transmission, you can not confirm your pinion angle or driveline angle, until you measure every thing correctly.
You can install stock A-body front hangers and shackles and reset the pinion angle based on the transmission centerline NOT to the ground, NOR to the driveshaft.
In other words, AFTER you correct the hangers and shackles, when the vehicle is resting on its suspension, make the pinion parallel to the transmission as a base-line, then roll the pinion downward 2 degrees and reweld or shim your perches. The result is a true 2 degree negative pinion angle.
