You didn't give us enough information to go on.  The GAMI thing started with the Continental IO-520, which had an intake manifold that produced an airflow imbalance - some cylinders were getting more air than others.  With a normal set of injectors that presumably gave an equal fuel flow to all cylinders the result was that some cylinders consistently ran leaner than others.  If a careful "lean test" was performed a set of injectors could be custom made that "adjusted" the flow to each cylinder in a way that resulted in equal air/fuel ratios.  Another issue was that any set of injectors would have fuel flow variations due to manufacturing tolerances and combined with air distribution variation would result in large errors.  Their idea is you send data from a lean test and your existing injectors, labeled as to which cylinder they came from, and GAMI would give you back a set that was matched to each cylinder.  The key is the lean test, where several data points, each including all EGT's and the fuel flow, were taken at ever-increasing air/fuel ratios with at least 3 data points rich of peak and 3 lean of peak.  Send the data to GAMI and they will tell you if a custom injector set will help.  It's not whether one EGT reads higher than the others, but whether it peaks at a different point than the others.  I have an Excel program that will analyze the data, so you could send it to me if you like, or post it.

And to answer your other question:  An injector is essentially only an orifice and it will maintain its flow virtually forever unless it gets dirty or is damaged, usually by a misguided attempt at cleaning.  There is no "setting."  This is true of both the factory and GAMI injectors.

I think you will find the people at GAMI are straight shooters.  I sent them data from a Lycoming I had and they said they couldn't improve the distribution enough to make it worth buying their injectors.

 

Gary Casey