Ideal Direct Vacuum Source for Vacuum/Econometer Gauge?

[ascendedmind]

Where is the Ideal Direct Vacuum Source for a Vacuum/Econometer Gauge on a 1985 CRX HF intake manifold?

Is there an ideal location where the mechanic can unscrew a plug in the intake manifold to screw in a barbed manifold fitting or a suitable vacuum hose where he can cut to splice a barbed T-fitting into?

(Not intake brake booster or other accessory line) Remember, this CRX has a 3 barrel carburetor with many vacuum hoses. The car runs & idles smoothly.