The biggest you would need are 65 lb/hrs so knock down the pressure. You might try going back to your stock TBI unit and adjusting that....might make a world of difference.

 

Mods are bigger throttle body, it was bored out, but still uses the factory injectors. It has a pro-jection intake, MSD 8.5 wires, EGR Delete, the Hydrolic roller cam, roller rockers and lifters. 30 over with flat tops and balenced. World Products Sportsman 2 heads. Shorty Headers by edelbrock, no cat, Magnaflow 3" in 2-2.5" out exhaust. Custom chip from TBIchips.com Holley HP fuel pump. I'll try turning down the fuel pressure a little more and mess with the timeing a bit. Maybe that is all it needs, what spark plugs would you reccomend?

 

AC delco are good....NGK are about the best from what I've tried and heard about.