Here is a shot of the rear of the transfercase showing how much room I don't have for a disk.
I like the cog brake idea too, but I don't have time just yet so I plan on having a hand brake that pulls the brake pedal down. So long as the hydraulics are good it will hold all four wheels.
![Fingers Crossed :crossed:](https://board.marlincrawler.com/Smileys/marlin/crossed.gif)