SLIDER1

I have found a brushless motor,..but the shaft size is 2.3mm......I have seen other motors such as momba,.....but they have a shaft size of 2mm.....do you think that i'll have trouble withtrying to find pinions to fit this motor???or,........is the two sizes so close that it wont matter????.thanks for all the help in advance...........this is for a 18 scale,mini slider..........