Any thoughts on this engine issue

I think the answer is right before your eyes,, the plugs are showing rich,,, 2nd hint,, when pulling off vacuum hose,, it speeds up,,it needs to be leaner..

didn't catch if you had a pcv or not,

the surge is called "hunting",, its trying to find a happy place to run,,, until you lean it out,, it prob wont run any better,,

cure the richness.. clean the plugs, run it, and read the plugs,, they'll tell you ..