383 running like s#%t.

I finally got time to dig into it today. After running on high idle for 3-4 minutes I checked headder temps with IR heat gun right at the head. #1 259, #2 248, #3 290, #4 220, #5 165, #6 415, #7 95, #8 301. So #7 is for sure dead, I swapped plugs with #5 and no change. I swapped wires with #5 and no change. Fuel filter looks clean yet. I am wondering if it is fuel or ignition related? Maybe the old points aren't firing correctly on all cylinders? I have to see if I have a gasket for the carb so I can tear it apart and clean it. Any other ideas?