I run a Novak Super Rooster with (2) 15t firebolt motors and a 5000mah Trunagy lipo pack.
I my out law truck I run a Novak Super Duty with (2) 10t Trinity Speed gem motors and a 5000mah Trunagy lipo pack.
I get about 5-10 min run time
Are you running a stock chassis or a after market chassis. I would say go with a 15t to 17t motor that way you get descent speed w/ longer running time.