Without looking at the truck and the work that was actually done, I'm only guessing...And guessing from my own personal experiences....So here goes: A vibration is something moving at a given frequency - Tire out of balance/out of round is moving up and down, driveshaft out of balance/out of round is moving up and down, or binding, etc. You can narrow those down to location of the vibration.
But, the only thing an alignment does is set the position of the wheels in relation to the centerline of the chassis. Theoretically, if there is no wear in any of the steering parts, the wheels will rotate on the axle with no upward or downward movement, no matter if the wheel is canted outward/inward along the centerline(camber), turned toward/away from that centerline (toe), or leading/trailing the axle centerline (caster). On an independent suspension vehicle, total toe is not normally zero as this helps to stabilize the wheels from shimmy...Positive caster forces the wheels to point forward. Your total toe is positive and your caster is positive and balanced, so that thing should steer easy, return to center after a turn, and not shimmy(positive toe).
ASSUMING ( I hate that word) that you are absolutely, positively sure your tires were not doing this prior, then what changed? A) The rear driveshaft angle...That'll cause issues if it's too steep. B) The front shaft angles... Your vibration is in the steering and pedals...Kinda points to that. Using a spacer kit to drop the differential would solve for it. C) Damage to driveshaft when it was put on the rack...a little ding will do 'er.
These are my best guesses, and that's all they are.
