vibration after 3.23 to 3.91 swap

Are the balance weights still on the drive shaft or did any get knocked off during the swap? Look for roughly 1-1/2 inch long by 1/2 inch wide y 3/16 inch thick tab weights plug welded to drive line. Is the drive shaft straight and not too long? Were bores clean in the pinion yoke to keep from crushing bearing cups to an oval shape, flattening needle bearings ? Is it a crush sleeve rear end? Is end play on axles correct? Its hard to tell by a video,but it sounds suspiciously like a rear transmission driveshaft bushing that has an egg shaped bore or a pinion bearing. Was it a gear swap only or an entire rear-end swap? Hope this helps, but with out actually being able to crawl under it to shake things around it's kind of a crap shoot...