Vibrations at 60+mph, shops have different opinions...?

Hey guys, dealing with another problem...

I've got this driveline vibration at 60+ mph. Stock ride height, no lift. Brand new tires, have had them balanced twice. Carrier bearing seams tight and in good shape. I've already installed new u-joints.

I have had 2 shops tell me that I had positive pinion angles and that the driveshafts were likely binding on themselves (because it's a 2 piece shaft). So, I had a frame & alignment shop throw in 1.5 degree shims which seemed to clear up my vibration at 40-45mph, but my 60+ mph vibration is still present.

Rewind to when I rebuilt the motor 12 months ago. I took the driveshaft out and to a local axle shop and had them balance the shaft. They are the most popular axle and driveshaft shop in Indy.
So the first shop that installed the shims, suggested that I take the driveshaft back and have them re-balance.

Yesterday I dropped my truck off at the driveshaft shop and told them to re-balance and fix the vibrations. I got a call today from said driveshaft shop. They are blaming the majority of the vibration on my motor, but they think that the rear u-joint is too tight. So I told them to pull it and inspect. This driveshaft shop said that I need to take the shims out because they aren't helping.

So what are your opinions?
Isn't it basic knowledge for "driveline specialists" that you aren't supposed to have the pinion nose pointing up, but that it should be parallel to the carrier bearing?

Had the driveshaft rebuilt. Knocked down the vibration a ton. I still have a vibration though. Cruising at 70, turn the truck off in neutral and the vibration goes away. Whatever is left has to be motor. Any tips on where to start?

Did you have any of the internals on the engine balanced. An injector misfiring can cause a very slight vibration. But I have yet to see one that amplifies through the entire power train.

Also. Check your motor mounts and trans mounts. As wear on the mounts can cause an issue as well. The Trans mount especially. To keep it simple I would start with mounts. I know from old experience that the crowed rods did NOT come balanced from the factory. And needed a good shaving. Also could be a bad balancer. Now that I have seen cause some awkward vibrations.

Tranny mount was replaced when motor was rebuilt, motor mounts were not replaced though, I'll check those. The machine shop said they balanced the rotating assembly, they even asked for my billet flex plate for the balance. I have a new ATI balancer that I can throw on. Do I need to remove the radiator to do that?

it depends on whether or not you can get a puller between the radiator and the hub... Which i doubt... Its been a very long time ago but i pulled my radiator on a old 7.3L I had. Might ask that question in the 7.3L forum.

The damper is a stretch, just a possibility.