consistant misfire out of nowhere

Classic fuel system symptoms. The FIRST thing I always do when I get an older car is automatically remove the gas tank, drain it and clean it. You cannot expect a thirty plus year old tank not to have sediment and rust buildup. Unless you fix the SOURCE, you will be forever having the same issue.

The pump sucks trash out of the tank, puts it through the filter and into the carburetor. The filter eventually stops up. You replace the filter to get it running again, only to find the carburetor is messed up from the trash from the tank. Clean the tank, replace the filter again, remove disassemble, clean and put a kit in the carburetor and you will fix the problem. Anything less and you are pissin in a fan.