Signon and then go to the tuning section of for GEN2.
I did a great number of VEC pieces there.
I take it your logging already? Or did you get the 12.3 from a gauge or meter?
You will need to really do some VEC logging across the full RPM range, only then does it make sense to try to tune yourself. Is it easy? Yes, with logs. Can you do it? Definately, with logs.
In any event, if yuo get stuck PM me, if I can help you further.