I recently got a used KB and have been reading about the high speed pinion that comes with it in order to reach 50 mph. Well my car being used I have no idea what the high speed pinion gear tooth count is or what the spur count is supposed to be. I have the 2 batteries (Traxxas brand) the connector but wanna make sure I got the right pinion and spur. Any help would be appreciated. Also can I run 1/16 slash tires on this to give a little more grip? I have a stock set laying around and didn't know if it would change anything in a negative way. Thank for any help.