I have an Avid Triad slipper with 69T spur that I simply tighten all the way down. Looking at a slipper eliminator but doesn't look like there are any "drop in" systems available for the RB6. Speedtech turbo hub says it's for the AE/Losi buggies. They're sold out on the site anyway.
Yep you need an avid top shaft for it to work. Custom works I got but its sloppy. Tower hobbies sells it. Both need the avid top shaft.