I will tell you right now that 7" of slip will not be enough. Over the years I have ran 14", 12", and 11". A little secret, the IFS single joint on the front d-shaft has the most angle of any stock D-shaft. Also by doing the CV mod I gave you the link to I was able to get 38-40 degrees out of my IFS CV. If you want an awesome, heavy duty front or rear d-shaft check out Dave'z Offroad Performance
http://www.davezoffroadperformance.com/forum/viewtopic.php?f=3&t=296