Drive shaft numbers?????

I have a 1997 4 door XJ with 4.0 ax15 231 and an 8.25. I'm moving up to 8inches and i need the drive shaft done before i put the lift on as it is my DD. I'm using a front shaft and obviously having it lengthened.
I need a few numbers.

-What is the at rest measurement from center yoke to center yoke?
-how much exposed inner slip should there be at that length in order to have proper compression length?

I appreciate the knowledge.

wow was it something i said?

Probably not, its just that to measure for a new driveshaft, you really need to have the vehicle at the height, and measure from there.

You really can't ask other people what their at rest measurement is, because every vehicle is at a different height. The possiblilty of someone havine the exact same distance from yoke to yoke is pretty damn little. You also can't just add 8" to the stock number, as you could possibly get more or less height than is advertised. Thats probably why you haven't received any responses.

I understand how to properly measure lift height and was hoping someone else with a true 8" would step in and help me out. I'm just looking for a ballpark. I'm obviously going to make some measurements my self.

The main question i have is about the slip. How much should be exposed at ride height?