[jagarra]

I plan on using one of those stethoscopes to try to isolate the noise. I cleaned the lines using carb and throttle body cleaner. I would cap the end fill it and let it sit over a couple days then drain. I did this over a period of a couple weeks. As far as I could follow, the vanish extended to the filter and pretty much stopped. Filter housing was removed and cleaned up, carb rebuilt.
I too am thinking that the noise may be associated with the interference issue. I will see if the smoke clears up, if not ,then I may have a ring problem.

When I put the distributor back in I set the timing statically about 10 degrees BTDC. Didn't set the dwell. The noise doesn't sound like pinging, too deep, no load.