mod 1 IS the pitch. i dont really know why some gears have a # for the pitch and some are a mod 1 or mod .08(like the epx pros)

the pitch is the angle of the teeth. this stays the same no matter the number of teeth.

so, if you get a 17 or 18t pinion that says mod 1 (or module 1) it will have the correct pitch for the 8e.