How much is it lifted? Doing the math you may need twice the yoke spacing than a stock truck. The yoke will slip maybe twice as far as stock. :

HOdiesel

 

I have done this modification to 3 trucks, with no driveshaft trimming, and have never had this problem. One thing that had to be done was to trim the front bearing retainer on the NV4500. None of the trucks I did had been lifted, so axlewrap may be a factor on your unit.
Just my 2 cents. Good luck.