I had placed the holes for the trays years ago. Has it really been that long?
I had to ream out the holes for a #8 screw. That all went pretty fast. From there, I mounted the trays to the newly made support bracket. I did all that before attaching the mounting bracket to the instrument panel. That made the work simple and fast.
I had to disasemble each tray to make replace the "experimental" connectors with those for the Fast Stack cables. (Garmin doesn't sell direct - shops have to do some value add. Mine pre-installed the power wires and sent along a bag of DB connector pins.).
Figure three shows the completed, modified stack with the new connectors.
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Auto Pilot (Not shown here) Audio Panel SL40 Nav/Com GNS430 Nav/Com/GPS GTX327 Transponder