[QUOTE=F-BIRD'88;1668280]You can get rid of the manifold vacuum gauge fluctuation by dampening/restricting the hose with a restrictor orrifice.
Most dedicated manifold vacuum gauges already have this. If yours is not damped you will have to experiment with the orrifce size.
The problem is that one gauge in the cabin reads 12" vac cruising around. The cabin other reads correctly at 19-20. That one comes from the carb base.
It is not fluctuating up and down per say . Is this advice still for that?
In the rear you can see the boost signal port in side of the housing.