This is just the easiest and cheapest but still as good

 

You can buy the posi lock in a kit but its like $200. I did the same thing the kit does for like $40 and it can be done for cheaper. I thought about pulling the diff selct shifter from my landrover and using that for the t-case shifter. I got it out from the dash part but then realized I was to lazt to get under the truck and disconnect it underneath lol. Maybe one day I will get around to it!!