I ordered the trail tough diff cans for the 4.62s I'm still looking for. I've heard the trackkick front gears mated to the sami rear third member will not last, opinions?
 The other question is using the trackkick aluminum third member complete in the front of my sami will not last either (will crack around the pinion seal). Should I try this or just swap the gears to the cast sami third member
I know the flanges have to be drilled for the smaller drive shaft yokes, am I missing anything?
 Any Input would be very helpful as I haven't been able to use 5th gear since the lift and 31s

Although requiring a bit of precise torquing along with that handy retaining ring, replacing the ring and pinion gear in an existing samurai third member would be the most reliable method.  Steel thirds can be destroyed, but they will take a LOT more than aluminum ones.

New bearings and other wear item are good insurance for your swap!