information based on
Direct from Boeing with one proviso. I did not enter or use a bias value as that would be improper release of privileged data . so its a pretty bland generic B767 with its identity smudged out.
On the subject of engines there is a spread of a few percent between rival makes but these are subject to continuous improvement and different construction types age differently.
I can thoroughly recommend "Gas Turbine Performance" by Walsh and Fletcher. If you apply yourself to this book you will get to grips with how engines turn and burn. But never to the degree of a third decimal place in sfc for example.
Unless there is some really frustrating bit I have missed out, which I'll be glad to correct [disclosure rules permitting] I don't think I've much more to add.
Nice question though and it is a nice aircraft too.
Good Luck with whatever it is you are doing. Drop me a line if you are bemused.
Mathy