Give Richard a call

High-Gain Tuning
www.HighGainTuning.com
303-242-8336

He is very knowledgeable and has a very nice system that I heard some of the 250r guys have used.  You could pick his brain and get some pointers from him.  Let us know what he has to say also maybe get us a video of your zilla injected.

Also he mentions in a post that his throttle bodies are smaller then the same size carb, but I am not sure if he meant diameter or the throttle body itself.