Hardened Gears and 3 window bearings
 

I am trying to gather some information regarding hardened stationary gears as far as why they are better then stock? Also is there any reason to why three window bearings are better besides being more room for flow?

hardend stat. gears are harder than the stock ones, obviously, i think they're only used when u plan on making lots of hp/torque (250-300+) the stock ones are fine for n/a motors.
3window bearings allow for more lub'ing of the e-shaft journals

Hardened gears were used mainly for high rpm engines, seeing over 8500rpms. Same with the 3-window bearings. As far as hp goes, you dont have to have race bearings with really high hp, its really needed for engine operating at or over 8500rpms.