My 302 sounds like it is running on 7 cylenders. it looks like gas/ air is being pushed up out of the carb (a Mist that smells like gasoline.) I had the intake manifold off to day and replaced the gaskets as it hasn't run well since I put the maNIfold on. I was thinking vacume leak. not the problem. sooooo...what's next to check. I did notice when I had the manifold off, #1 and 2 cylenders had soot in the head. like it's firing back up through there. How do I tell if a valve is stuck open? what do I do if it is? thanks guys
Valves can stick open regardless of which ones they are.Sounds like you may have a burnt or cracked intake valve.If it was stuck open you would have a fire breathing carburetor. Simplest way to spot a hung valve...pull the rocker cover or pump compressed air into yhe cylenders you suspect are bad while they are on TDC on the compressoin stroke.
Remove the plug wire from 1# and see if it effects the car. If it does/or doesn't make a note and replace it, then pull number 2 and see what it does. Once you narrow it down, check the plugs.
You could put a vacuum gauge on it. If its firing back up the intake you'll see the pulse on the vacuum gauge. Compression test to find cylinder then like Mavman said put air in the cylinder with the valves closed and listen for the air leak into the intake,exhaust or crankcase. Assuming intake in your case.
