look up moser, any large axle building offroad rig company you can even get some cool "flashy" billet u-joint straps and some billet front shop trees and a bunch of other stuff even though i am with everybody else on sticking with factory. but if they are torn up replace them.

 

http://www.inchwormgear.com/store/in...c4b05af2189363

http://www.drivetrain.com/dana70.html

http://www.ringpinion.com/PartsList....pe=Stand-Alone