It could be the drive shaft carrier bearing if you have a 2 piece
One piece drive shaft.
Could be driveshaft yoke, or ujoints binding/worn, too. Check everything in the driveline.
I pulled the driveshaft, U-Joints seem to be okay?
I greased the yoke inside and out. It seemed to get a little bit better, but it is very much, still present.
I'll check the motor mounts next.
Hauled the RV quite a bit over the holiday week, LBZ purrs along very nicely.
Water pump weeped a little anti freeze and then stopped weeping (motor never got hot). Once I get the LML on the road, I may have to install a water pump on this truck.
A buddy of mine and his wife joined us on the camping trip, they drive a Diesel Ford Excursion. One afternoon I had had a few drinks, it was decided we needed to run into town, my buddies wife was the DD. She drove my truck, some kid in a LB7 pulled up next to us on US31, I was joking around and told her not to let him beat us. She puts her foot into it, he disappears behind us. She spent the rest of the week going on and on about how fast my truck is.
Kind of funny.