RC8 spur gear question

[DwightSchrute]

my friend is building a high speed RC8, and i know almost nothing about the buggy. are there any other spurs that can be used on this buggy? i seem to remember someone custom fitting a 36t on the center diff, but i can't remember what company made the spur.

also, does anyone know of a place besides kershaw designs that makes mod
5mm pinions larger than 26T?

any help is greatly, greatly appreciated.