Agree as well to the recommendations above. Leave off this vacuum retard. Cap off the ported vacuum fitting at the throttle. Set your dizzy initial advance to 10deg BTC and drive.

Vacuum retard in my experience was an emissions tactic which increased exhaust temperatures at idle to help burn HC. Also, before EGR was added, some engines had tip-in knock when throttle was opened with poor quality or low octane fuels. Remember, the 1800E was a 10.5:1 CR engine! But also there was leaded fuel back then.

Alternately, the 123 ignition distributor has a variety of advance curves, some including vacuum advance. But the vacuum signal must be taken from the manifold and not the ported vacuum signal at the throttle.

Vacuum advance has advantages at part throttle for torque and fuel economy and throttle response. As long as you don't experience detonation/spark knock, you are OK. I was a calibration engineer at Ford in the late 70s. In those early years of EPA emission standards and CAFE, we would calibrate to just the threshold of light knocking. We call this "the sound of fuel economy" :-)