Hey Phil,
I have the vibration at initial start, and it feels like the rear differential or some part of the drive line. Not the transmission. I crawled under my truck and everything looks tight. But I did notice I have these same type of witness marks, on my center support bearing. It has been...
Even with the rubber bumper removed near the latch it still will not latch. Place two washers behind your two studs coming off the back of the cab and it will correct the problem