I watched your video. Is the concern currently only with what you perceive as rough running? It will likely never run as smoothly as a newer fuel injected vehicle, if that is a basis for comparison. My 85 Jetta with mechanical injection runs smoother than my 64 GMC with a carb. That aside, have you ruled out mechanical issues-has the engine been rebuilt ever? If not, could there be cylinder sealing issues, or a burnt valve, or even a wasted cam lobe? Have you gone back to basics? When I diagnose a vehicle at work for driveability issues, even with a scanner, the basics apply. Do the cylinders have sufficient compression? Correct fuel pressure and volume? How strong is the spark? Is the coil on its' last legs? Check with a spray bottle filled with water and spritz the plug wires-you may have voltage taking the path of least resistance, i.e. to the block, instead of the plugs. Hope this doesn't cornfuse you more.
P.S.-When checking for vacuum leaks, I like brake clean. While much more flammable, it does have less surface tension, doesn't leave residue, and therefore is more easily ingested by a vacuum leak.
