hi i would just like you to hear what i did. I bought a mamba max esc 4600kv and 5700kv motors went to the shop and bought a xt po stuck it together put the esc and 4600 motor in along with a 5000mah 30c 11.1v battery turned the esc down to its lowest settings and gave it a test in the house it screamed like a pig so i tightened the diff and it was ok tuck it outside brilliant for about 3 min when it stopped the motor still ran but no movement stripped it down and it had totally melted the inside of the diff so if i were you i would be careful on how much power you try to get to the back wheels through that ball bearing diff.
ho and i no nothing about tyres except they are a ba----d to glue on.