Vibration and Noise Issue

It was some F body rear end before, pretty sure 8.25 from what I've found with measurements. The sounds is more of a scrape then the baseball card noise, it's sort of hard to explain. As for the driveshaft thing, if I hold a screwdriver lightly against it while it turns you can see that the driveshaft pulls away and goes back and touches the screwdriver like a u joint isn't centered, but wouldn't they center themselves? They worked perfectly in the old setup, and the caps all look even with the C clips to keep them all where they need to be. And it's not just like some piece vibrating, the whole car starts rattling your teeth. The steering wheel doesn't shake, but if my hand is on the shifter it's like holding a very powerful vibrator. I plan to pull the shaft and check angles the best I can today and see if the pinion yoke has any play in it. My dad and I were thinking maybe a bad pinion bearing that has enough play to cause an issue.