Need help converting to Brushless

[2FastSS4U]

So what you're saying is that the mount is good but the battery trays are good but only if I use lipo's because of the weight savings? I've seen a savage run a Novak HV4.5 on youtube and it looked impressive, do you think this motor could really push this heavy of a truck? Also I've been seeing these brushless savages with the stock dual disk brake system still working, whats with that, I thought ESC's were able to control braking as well.