670 holley avenger idle air adjustments?????

I highly recommend a wideband 02. They're not that expensive and they really simplify the process. The AEM is the way to go.

I am about at the same altitude as you are and my 5.9 liked between 1 and 1.25 turns out from closed.

Did your street avenger come with an instruction manual? It has some tuning guidance. Holley also has a DVD that can be helpful - it was included with the last street avenger I bought but you can find most of it on Youtube.

Good luck

Steve