E-maxx motor and gearing suggestions for grass

[tacoprerunner]

I have an E-maxx 3905 and after killing the EVX2, I want to go brushless.

I already ordered a Mamba Monster Max from Mike.

I'm strictly a basher and run mostly in my yard which is nearly all grass.

I don't need insane speed. I was actually happy with the stock speed on 16.8 volts, which was about 30 mph. Anything much faster would be a waste in my yard.

I'm looking for a motor and gearing combo that will survive running through a normal lawn and be able to run on 16.8 volts Nimh.

I'm not ready at the moment to invest in Lipo.

I was thinking of an 8xl geared 20/68 or a 9xl geared 22/68 which should give me a speed of about 32 mph according to the speed calculator

Thanks for any help