Should I mill my edelbrock performer rpm intake?

LovetheA's said
Well I’m pleased to report I took my edelbrock performer rpm intake to a machinist I trust explained the situation to him and had him mill my intake .040 on each side. That is the same thickness as the two felpro gaskets under and above the valley pan. The intake lined up perfectly now with the gaskets and I’m glad to report no intake or carb leaks. Checked for leaks with starter fluid previously based on the engine idling much higher than before it was taken apart. It used to idle at @1000rpm and with the leaks I had it idled noticeably higher at 1500. Now it is back idling at 1000 again. I sprayed the starter fluid at various points where intake meets heads and carburetor gasket with no sucking in of fluid or change in rpm as it did before. I hooked up a vacuum gauge to the constant vacuum draw on the side of my speed demon. At idle it currently has 10-12 in vacuum that is after I moved the distributor around to find the steadiest and highest vacuum reading at idle.
However it seems like I have another issue. The engine doesn’t idle as smooth as it used to and the gauge bounces around by about 2 inHg. I should mention that it is a 383 4 speed 67 Dart with the older Mopar performance camshaft 484 lift 284 duration. What would be my next logical step check plugs, wires and distributor cap or is idle mixture screw on speed demon carb off? Is there an easy way to do this without pulling all the plugs. Some are a bear to get to with TTI headers. I didn't touch the carb just put it back on after changing old cast iron to edelbrock performer heads and updating Harland sharps with Mikes geometry kit from B3 racing. I’m trying to get it running as smooth as it did before by process of elimination and learning as I go. I have included a video of the engine idling and the gauge. When I rev it up it also feels like it is running rough.

Running rough can be a lot of things....but you can kinda hear the idle jump around more than it should a few times, and the gauge reacts with it. I kinda doubt it's a plug issue, but there are quick ways to test for misfiring cylinders--ground one wire at a time and listen for a change, measure the header temp at each exhaust port, etc. New cap and rotor are cheap and if it doesn't help, you'll have a spare set.
Double-check your lifter preload and make sure they're all set evenly. I know you don't wanna hear this, if plug hole access is tight, but honestly (because it's easy for me) I would compression test all 8 before doing anything else.
It could be very well be a carb issue too, it's so tough to tell from the video..it doesn't take much sitting around for them to crud up. If you cleaned it good before re-installing; that's good. Get it back to it's baseline settings and go from there--ignition idle timing, float levels, throttle blade adjustment (T-slot exposure) and idle mix.
Oh! And double check the PCV and vacuum connections and make sure they're in good shape..and of course check all your ignition parts and connections. Goofy things can happen when cars get sidelined for upgrades..