Time to switch from the mandrel to the three jaw chuck. With the space held firm I started by drilling out the ID and then switching to the boring bar to get the final ID of the spacer.
After all of the cutting was done on the lathe I used a transfer punch and the driveshaft to mark the bolt holes in their proper location.
Here is the finished spacer showing the pinion flange side.
And the drive shaft side of the spacer.
And her is the whole reason why I wanted a spacer. Just my 1 1/2" coil spacer lift had pulled the drive shaft out of the t-case this much. I though it would be better to have more spline engagement back.