Hey Steve The VSI is just hooked to the static line of the altimeter, and airspeed indicator. You can use a venturi that is placed inside the cowling if you want to have it not show outside the plane, but that is going to be the easiest, most reliable way for a KR builder. For both an Attitude Indicator (Artificial Horizon) and Directional Gyro you will need the larger type venturi so that you can produce enough vacuum to run both. The largest venturi AS&S sells requires a regulator.
You should be able to see the fuel in the tube since it has a blue color added, without any ball in the tube. I can just see it melting over time and ending up in the fuel filter or worse Colin Rainey N96TA
