so stock gearing is 21.71:1

with 50t spur and 13t pinion on diff it is 11:1 (dunno if you would help me on this)
if so i would plan to run the 44t spur and a 23t pinion i should get a 5.5:1 ratio :027:

why you ask well at 27500 rpm with stock tranny it does what 25mph so at 400000 it must do around 38mph

so if the ratio is around 4:1 then i am hoping to run an out-runner brushless motor for more torque (5 to 8 times as much as a inrunner) and they run at about 12,000 rpm lets say so that would be the same as 48,000 rpm on stock tranny so 45mph :004:

these are very rough estimates.. but im looking at different possibilites, like you said the gearing would be high with this set-up