After a complete overhaul of the old tired Blazer and a four inch lift, I started experiencing some vibration from the driveline. All new u-joints, rotated u-joint in yoke, raised the transfer case, dropped the transfer case, generous lubing, new dust seal on the slip joint, etc. I finally pulled the driveshaft out last night and took it to a drive shaft shop here in OKC this morning. I got it back this after noon and they lengthened it 1 and 3/4" and rebalanced it ($110.00 worth). Well fully expecting this not to cure the problem, I put it back in tonight and took it for a run around the country side. It was like driving a totally different vehicle. So I took full advantage of it and burnt up a half tank of gas. What a difference it made. Looks like after winter here, I'll pull the front shaft and have the same done to it. Any way, just thought I would pass this tidbit on, and don't forget that tube that transfers energy from the mouse/rat motor to the meats.