I have not personally done rears up front before, but I think that the longer part (bushing to pin) is usually put in the rear to push the front axle further towards the front of the truck.
I don't know if it will work for you, but I have this 4.7 T-Case, 23 spline
http://www.pirate4x4.com/forum/showthread.php?t=691534I'd be willing to give you $100 trade for your stock top shift case if you're interested.
