Vibration over 40 mph.

I removed the shims and got back to 2.3 degrees up on the trans and 2 degrees down on the pinion which is the same as before I started with this whole adventure. These are real measurements with a protractor, no app. I believe @TrailBeast had the solution in the side to side alignment of the trans and pinion. It took a little doin' but I slid the slip yoke over about a 1/2 inch with a modification to my trans cross member and mount. If I make another one it won't be so damn tight. I had to get a sturdy pry bar in there and pry the transmission over and snug down the trans mount bolts to hold it. With that done, I reinstalled the driveshaft and took it for a drive.

Like magic! Vibration was gone. I drove it about 25 miles and by the time I got home, the vibration was back as before, so I think likely the trans slid back to it's previous misaligned spot on the trans mount. Obviously there is too much torque trying to keep it in the misaligned spot so I'll have to maybe loosen the motor mounts, line everything up and tighten it all back down. I even thought I may have to add some shims to the motor mounts at the block mounting ears if necessary. Has anyone ever had to do this? My only assumption is that with the 998 in there and a 7" longer driveshaft, it was not enough angle to cause issue.

Cley