I took castle creations suggestion and used the 5400kv, they said anything higher than that would burn up because the Half 8 is too heavy. I posted this to let this also be a lesson to everyone else thinking about using a Mamba in their boat. Boats require more torque, the Mamba's are meant for small applications. and if you put one in a micro boat make sure you use the 5400kv or less. My half 8 runs fast and smooth, the only other 2 upgrades are oil filled shocks and 8 cell battery. I would say it is 3 times faster than stock.
For the sake of Eyekandy's thread, for anymore info on my half 8 please email or pm me.
PS The Kyosho Half 8 Mini Inferno is very cool and the hardware is true to Kyosho's quality. Very nice right down to the last detail.