But, you should be talking with one. Without an experienced Avionics
technician making the installation, it likely won't become an IFR
installation. The paperwork is a moving target, but is a lot easier today
than a few years ago. Whether it involves a 377 is academic becuase, if it
does, the competent shop will take care of that in course.

I have a certified Avionics shop do the install