Tom:

Another thought that I forgot to mention.....Be very careful of magnetism.   I ended up having to move the flux gate transmitter for my HSI because of magnetism..  Found out that all the nut plates around the aft access door were causing a problem.  Had to replace them with click-stop nut plates/  Then I found out that the aft fitting on the autopilot bridle was steel. DRAT   Had to have a new one made from non-metallic material.  BUMMER

My flux gate requires 18 inch separation from any magnetic field.  Thats when I discovered really how much of a problem I had made for myself.

Happy Building, Bill Hogarty