Google how a closed loop mass air flow efi system works. It was probably in the January 92 issue of super chevy if your jitterbug won't do google.
LMAO this is funny. So you think those narrow band 02 are going to adjust and make all the difference in the world if you make major changes to the cam and cylinder head?
Since you seem to think you know so much about EFI i'm sure you know that narrow bands on read out to 1 point at most in either direction and only edit the closed loop fuel tables to try and obtain stoichiometry when cruising right? When you are accelerating or WOT the PCM doesn't even use the factory o2s. The truck is open loop at that point, reading the base VE and fuel tables. It compensates for weather temp and humidity off the MASS, MAP, and IAT sensors and works out the fueling using the base map and acceleration enhancement table and applying those values to whatever timing values are in your IAT modifier tables for any correction in timing that is needed.
I think you are the one that needs to do a bit of reading up on the subject.