Bud,
I’m sure you did all the following but I will list all the things I can think of anyway.
* Install a pressure regulator and gauge.
* Set the pressure to 4.5 to 5.5 psi with the engine running.
* Readjust the float levels with the gasoline just at the bottom of the screw holes.
* Check the two 5/16 inch vent tubes cut at a 45 degree angle that stick out of the top of the carburator. Make sure the air cleaner top doesn’t come in contact with them and block them off.
* If you are still having problems, pull the float bowels to make sure there isn’t dirt passing through the float valves.
* Replace the float bowel valves of you haven’t already.
* While you have the primary bowel off, pull the primary valve body off. There should be no gasoline behind the power valve. It is common for power valves to leak and cause flooding, especially if you have recently had a backfire. It’s easy to have a backfire prior to getting the distributor adjusted.
* You can check the valve by sucking on the end, plugging the hole with your tongue to see if it will hold a vacuum. Or, replace the power valve with a 6.5 psi valve just to be sure.
* Replace the float bowel and valve body gaskets with the reusable blue foam gaskets. It is IMPORTANT that you use the proper gaskets with ALL the holes in the proper places. Using the wrong gaskets is a common mistake because there are so many variations and the differences are not evident. If you use the wrong gaskets, you will either cover up a hole and have poor power, have a problem re-assembling the carburetor or have a leak some where. I have done all of these.