Bob, thanks for pointing out that issue before I run into it. I have several spare hex hubs that are even thicker than the 6mm hubs you have. They are from front 2WD Traxxas Rustler/Slash/Stampede. If these 8mm hex hubs are too wide, I'll look into something like what you have.
http://www.hopmeup.com/Items/tra3654...ler%20Stampede
Let me know if these 8mm wide hexes wont work and I'll order some 6mm.