I drilled and tapped the manifold plug for an NPT vacuum port. I used 3/16″ flare-fitted brake line for the connection to the vacuum can. I tried to make the bends as nicely as I could, but I’m not great at that kind of thing. Works though. Note the dual-carb Fenton intake. Period hotrod shit that probably offers less performance than the trouble it’s worth setting up. On a 235ci Stovebolt is like nipples on a toaster . . . makes no damned sense.