Since you switched carburetors as stated in your first post and it made no difference, it may not be a carb issue (unless both were messed with). Check the cap and rotor for corrosion or cracks. Use an ohmmeter to check the ignition coil and spark plug wire resistance. It's more precise and reliable than a simple disconnect-a-wire test.
Also check EGR valve and again, the hose routing and connections for leaks. An EGR that doesn't close completely will cause rough idle. Same with a disconnected or miss-routed hose. You can use the propane method described in this blog, but do it outside to be safe:

Propane Trick.docx

The propane method is like the factory recommended procedure to adjust the carb mixture screw. Got a vacuum gauge or pump? It can also help diagnose vacuum leaks, valve issues and timing or carburetor setting faults as well as when adjusting the carb settings.