I had an interesting discussion with other pilots about converting my
Piper Cherokee 6 to all electric. This would basically require
replacing the AI and DG with electric AI and elec. HSI. So, then,
there would be no use for vacuum pump. But, one pilot said that the
certified elec. AI only allows for installation of the unit, and that
the FAA would *NOT* approve full removal of the vacuum instrument if
it was delivered and certified with the aircraft. Any experiences on
this?

My goal would be to put an elec. AI and HSI in the panel, dump the two
vacuum guages and also dump the vacuum pump (some weight savings!).
Has anyone done this successfully?