Right away my mind says its not in the tune...

Back up even further...
Check/change fuel filter, check/change plugs etc.. etc..
What plugs are you running?

Lets just say for the sake of arguing... if it is in the tune, what a/f ratio is the tune set at? What timing is it for? What numbers are you putting down.. (I know right away you are saying, what does that matter, but it does) What are all of your mods, and did they tune for each and everyone of them?