Will work. I installed new avionics in my Mooney M20J last April.
Righly tight....
Take a look http://gallery.payinter.de

If you plan to change something... do it right and change all parts that
you desire, because it is really a lot of work to do so in a Mooney.
One of my old rRadios was wirking only 50% and after trying 4 radios of
the same type to replöace my radio with a working one... and no one was
better than mine, I decided to do a complete redesign.

Which Mooney do you have?

Maik

Robert M. Gary wrote:
I have a slot in my very, very tight panel that current houses my
MX-170 (digital replacement for the KX-170B). How does the size of the
KX-170B tray compare to the GNS 430? I'm wondering how major the
surgery (i.e. inches of addition space required) must be in my Mooney
panel to fit the 430 where the 170B was?

-Robert