tdubis

Just bought a vacuum gage and was wondering where a good place to hook it up to get readings on timing, carburation, etc... Thanks,
Tom

joe_padavano

The vacuum gauge needs to be connected to a manifold vacuum source. One of the vacuum taps on the intake is your best choice. It's OK to use a tee if needed.

pcard

If you are doing this for tuning, could you disconnect the power brake vacuum line and use that as a source?

joe_padavano

Yeah, but you'll need a reducer to get down to the diameter of the hose on the gauge. It's usually easier to tee into the line for the vacuum modulator if the car has an AT. Also, most carbs have a manifold vacuum port on them.

tdubis

Thank-you for the tip Mr. Padavano and Pcard! Found a spot on the intake near the carb. Reading about 18in with a steady vibration up and down between 17 and 19. Could this be caused by the exhaust leak I have at the header gasket? Thanks!