On Thursday, May 16, 2019 at 11:44:36 AM UTC-7, Jj wrote:
"Further investigation lead me to the
simple 337 route and my IA was good at accomplishing that."

So I'm curious. Unless a 337 is used for a field approval, it is just a documentation of work and inspection form for major repair and/or alteration. It still needs the documentation of the approval to perform said work.

Can you share what was on your 337?
What approved documents or was it a field approval, aproved by your local FSDO?

Why does an ADS-B Out install need a field approval? It should be a minor alteration. This has been covered on r.a.s so many times, you can search the previous posts here.

The FAA describes very clearly exactly what is needed for an ADS-B Out install, including use of the 337: https://www.faa.gov/nextgen/equipads...r(9-25-17).pdf. Read it and follow the steps.