I've see a Jammin X2 crt with an RB concept TM928 last week-end at the race track, and OMFG[X(][X(][X(]this engine is a brutal beast.
It was more, and when i say more, it's MOREEEEEEEEEEEEEE powerfull that a full mod Novarossi 528XR.
The guys run it at 202*-215* range and it was stupidly fast, can keep the front wheel on the groud. He have pair it with an JP-4 pipe, and believe me, this combo is killer
I've a good deal on a brand new RB TM928, and i think to put that in my MBX6T.