Hi all- We're about to do a G5 HSI install, keeping an existing Attitude Indicator and the vacuum system that drives a century autopilot. I was looking at the vacuum setup and noticed that the vacuum suction gauge comes off a second AN port on the DG.  The attitude indicator lacks a similar additional port.    I'm gathering accouterments for this part of the installation.  I'm thinking the most simple acceptable way to do this is to measure the suction from the line on the vacuum