The Stovebolt Site Forums The Shop Area Engine Shop firing on 5 cylinders

I am looking for help on what to check on my 235 1960 6. I noticed it hasn't been running as strong and didn't sound smooth. So set the timing and points.running better but not normal. Starting pulling spark plug wires of to hear the difference started in the back firewall and came forward got to the second one engine didn;t sound different. Pulled the plug it was black and crusty, so I put a new plug still no difference the plug wire has strong spark. the first plug was burning normal. Any help would be appreciated.