If you want to mount and use these motors without any modifaction you will need to use the gearbox that comes with them. This can, and has, been used by many teams.
You will need to find some way of connecting/mating the small "fins" that are the output of this gearbox to whatever you want to turn...
I believe that the gearbox is in the 120:1 or so range so it has lots of torque.
You can get an adapter for the gearbox @
http://www.householdappl.com/cgi-loc...html?E+scstore
$4.25 74460-2249 - Power Wheels replacement wheel driver $ 4.25
I believe that this will work with the kit FOP gearbox...
They used to be included in the kit awhile back...
I hope this helps