Rough running 318

Lets start by checking two things. Engine off- pull distributor cap off and inspect rotor, is it solidly in place with no obvious damage? Look at the underside of the cap- are all nine of the contacts OK? Look for "carbon tracks", little dark marks/lines (look like cracks) that are really voltage arcing to ground. Replace the cap and re-confirm that the plug wires are properly routed. If all is good let's go to engine running. Start the engine and idle it down to where the engine just runs. Take off the air cleaner. Put your hand over the carb blocking 80* of the air flow. With the engine now starving for air (running rich) does the engine RPM now speed up? If it does speed up, this indicates that the engine is normally running lean and we have a carb/fuel issue or a vacuum leak. If manually choking the engine doesn't speed it up (but now wants to die), we have eliminated that possibility.