[storm9c1]

A quick fix might be to unhook the driveshaft from the pinion yoke, rotate it 90 degrees and bolt it back together. I usually mark the position of the driveshaft on the yoke before I pull one apart to ensure I reinstall in the same position. Maybe the shop didn't.

Keep doing this (unbolting and rotating 90 degrees and taking for test drives) until the vibe goes away or you end up back to the original position (be sure to mark the original position so you don't forget).

Might be an easy fix.