More speed than an 8XL can provide? I would say take a look at your gearing first, and see if there is the possibilty to gear up without overheating the motor &/or esc too much. The Bigjoe tires will slow the setup you have down, and also force it to work harder since they are very heavy- better off with some lighter bowties or mashers for those 40 series rims. Checkout BrianG's calculator for more gearing/motor options:
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