Can’t remember where or when I saw where it was an easy fix to install a vacuum port. All you had to do was drill the base plate into the primary bore. It was relatively easy to see where you need to drill. if you are interested I have another 9292 1980 truck 750 cfm,that has an altitude compensator, an idle stop solenoid to cushion the throttle return to full idle, and 2 ported vacuum ports plus full choke hardware. It needs a through cleaning and a kit, this is a complete unmolested carb. If you’re interested send a pm. Thanks