For some odd reason, my 350 is missing one one cylinder regularly, but not every cycle...if that makes sense. I checked the header tubes using my infra-red heat gun to see which one was not running, and found one significantly colder than the others, so I figured that was the one. I pulled the plug and found it looked rich, but not wet. So, then I ran a compression check on that cylinder and found 150psi of cranking compression which is plenty for it to run, and it also proves the cam and valvetrain are not at fault either. I replaced the plug wire with a new one with no change in performance. I also tried fine tuning the idle mixture on the Quadrajet with no change to the better. The vacuum gauge vibrates back and forth rapidly over a span of around 4 in/hg, but that only verifies a misfire. The plugs are almost new too, so I did not change the plug in the offending cylinder. I also pulled the distributor cap ( which is almost new) and checked but found nothing wrong. Now the car has been sitting for a while ( about a month since I last ran it) and it didn't have an issue last time. It also has fresh gas as I ran it out last time that it was run, so I needed to put a gallon in to get it started. I have checked the vacuum hoses and found none that are broken either. The car is also popping through the carb on heavy acceleration, so I may try to stiffen up the secondary air valve spring adjustment and see if that helps. The carb has stock calibration for a 1979 350 but with a K hanger instead of the stock one. I want to put in a new distributor eventually, but really don't want to put the money into that until the car is painted and mostly assembled. (There's no sense putting that money into it while the car is not usable.). I want to drive it to the paint booth this Thursday, but it's 30 miles away and I don't want to drive it if it is not going to run right. Any ideas?