What to hook vacuum guage up to?

[71swb4x4]

I was just reading franko72's thread on vacuum guages. Does it matter which line it is hooked up to?

Shawn

[Gee_Emm]

I hooked mine up to a port on the carb, you might have to get a "T" fitting so you can add an extra line.

[daveh6772]

If you put it on a carb fitting, make very sure that it is an actual manifold pressure tap, not a "ported" one that changes signal when the throttle blades open.

Ported ones like you hook the vac advance line to will give you false vac readings.

Best place is a fitting directly on the intake manifold, no chance of errors with that.

Vac guages are kind of cool. They are often sold as "Economy" guages, or some such, because they can help you learn to drive with a right foot that can get the best mpg out of your engine.

Every time you put your foot in the carb, the guage will drop way down. If you practice accellerating while keeping the guage as high as possible, you will see an improvement in your mileage. If you have a lead foot, it could be a big improvement.

It will make you a smoother, more consistant driver if you practice.

Of course, every now and then you have to ignore the guage and stomp it. ;-)

Dave Horn

72 K20 CustomDeluxe, original but now hot 350, TH350, NP205, 4.10 lockers
72 Custom/10, hot MercruiserMarine 305
67 CST, Vette 327, CR4spd, factory buckets
88 Cherokee 4.0 (wife's "car")

['68OrangeSunshine]

In my application, L6 292, Clifford headers, Offy intake, Holley 390 cfm-- I used the threaded port on the side of the Offy intake. It reads the state of flow inside the runners, and doesn't interfere with the carb operation.