Having trouble with gears

[James]

I bout a bk wanderer 12s and i cant find a pinion gear that will work on the 5mm shaft, and have a 48p.
I bought the 2 mod1 pinions, and 31p pinions, before i knew anything about pitch. Is there a 31p pinion i can use on the Associated RC10T2, or a pinon that has 48p, and i can drill out to 5mm bore (I tried this on a regular pinion but there wasnt any thread left for the set screw). Is there anyplace that can make pinons? Is there is how much would it be.

If there is no way to make this motor work on this truck, can i return it and gat a feigao 12s? Does the feigao 12s have a 1/8 inch shaft?