67 Dart 270...Project Old School

After I installed shims to get the pinion pointed down 3 degrees, I was still getting drive line vibration when the driveshaft hit 3200-3300 RPM going down the road (60-61 MPH). I ordered up some 6 degree wedges and installed them. This has the pinion pointing down at 5 degrees. Road testing showed some improvement. Low speed vibes are all but gone in the 45-55 range. I am still catching a small about of vibes from 60-65 MPH. I will eventually have to pull the driveshaft and have it checked out. I think it could stand to be an 1/2" shorter as the front yoke pretty much disappears into the back of the transmission. The transmission seal is very close to riding in the radius where the yoke flares out to the U-joint flange.