Personally, I'd save your money and leave the maxx as a SB truck. By the time you buy all the "beefing up" parts to handle the power, you will be $250-300 into it. And you will still be left with 1/10 diffs, trans and axles. Which all can be upgraded of course, but then your money into it goes up considerably. $100 for RRP gears in the trans, $120 for Maximizer diff cups w/RRP diff gears, MIP axles (or something similar).
By the time you have a functional truck that is relatively durable, you could have easily bought a savage, aftershock, LST, MGT roller to put that engine into and you would be starting with a platform that is much better suited for big block power out of the gate.
I've had a BB maxx. IMO, it's gone the way of the dodo. There are too many other options out there that are better from the start rather than to try to force your t-maxx to be 1/8 scale.
Just my .02