I didn't see that you wanted the shaft measurement and the spline count until late last night, and yesterday I got all caught up in working on my truck and forgot I told you I'd get the info, sorry. Its going to be probably Tuesday before I can get the info for you, Sunday and Monday of the Holiday weekend are my wife's time.

The only reason I can see for the sliding shaft would be for serious 4x4 off road action. I suspect that in normal on the road driving, the shaft probably doesn't move, or would move very little. For the shaft to slide in and out, the cab and frame would have to be moving in different directions. The only way that's going to happen is at the body mounts, and frame flex.

Where in IL are you located? I'm in Freeport, 30 miles west of Rockford. Gene