How big of injectors can a stock F22B1 take before its too much? I know stock are 270cc. Would larger just flood it?

 

if you have a stock engine or even a stock engine with bolt ons then stock injectors work. if you are boosting or have a rebuilt high compression cammed all motor setup then you can probably make use of larger injectors.

 

That what I figured. I just see lots of 550 and 650s forsale and wondering if they underfeed for emisions or something.

 

nah those are for high horsepower engines. when you make double stock horsepower you need double the fuel flow. you could put a set of the 550s or 650s on your car...but yo uwould need to tune it with programmable fuel management or it would just run super rich and lose power and have terrible economy.