a833 OD vibration in 4th gear at 3000 rpm

Might as well add my story. My 833od has a vibration at 40ish mph when shifting to 3rd, gets worse in 4th. 1-2,3rd, 4th under 40mph no issues just a whine in 4th only.
Any speed past 40 in 3rd/4th the vibration is there. And its severe.
Can't take the car to 40 in 2nd due to my rpms are maxed out. Taking to 40 in 3rd the vibration is livable, but shift to 4th and the vibration is strong, go faster and it gets worse, shift back to 3rd its still there until I slow down below 40.

I had it on jack stands today and it will shake the **** out of you when shifting to 3 and more so in 4th. But looking at the shaft, it looks true.
I've rotated the pinion yoke 180 with no change.

It had a 7 1/4 in it, no vibration that I can recall, just the 4th gear crying noise.

Now, has a narrowed 8 3/4 and a new driveshaft. It's been doing this since I got it together, Installed new leaf springs yesterday, added a 2degree shim front/back no difference in vibration. The pinion looks nose down but not severe. The tailshaft is nosing down just a small amount but looks pretty parallel with the body. So looks like the pinion is down a tad more than the tailshaft with the shim.

I'm considering calling the shaft shop and having them recheck their balancing and if that doesn't fix it, i'm leaning towards the transmission.