48 pitch pinions?

no no, its not the speed im worried about its the spacing between the pinion and spur, i only have so much room, plus im using a xl motor which has a 5mm shaft, so everytime i want to switch pinions i need to order a new one, so thats why id rather have one 22t pinion and then mess around with spurs, which i thought would be easy to fine one, but is proving otherwise.