The Jato spur & Rustler VXL uses the same slipper design, its just the pitch is different as the Jato is Nitro (0.8 pitch = 32pitch), so thats a straight swap:
http://www3.towerhobbies.com/cgi-bin...ARCH=jato+spur
And the Emax pinion fits a 3mm shaft (as used on most 1/10th Engines) and is 32pitch.
http://www3.towerhobbies.com/cgi-bin...CH=emax+pinion
This does however stop you running a gear cover on your diff, but you could probably make it fit, I didn't bother. I never had issues not running a gear cover.
Hope that helps