After two years of trying to get it tuned, finally took the advice of many here on Moparts and dumped the Edelbrock 750 carb. Engine is mild 440, stock intake and exhaust manifolds, 10 to 1 compression, little more aggressive cam than stock. Put on an Edelbrock 600 carb and new plugs and it's running better than ever. Plugs that were removed are Autolite 85's. All plugs were black (not wet, but black). Does that mean the 750 was running too rich, or is the plug too cold? Before going to different plug, I'll put some miles on the new carb, then pull a plug and look at it. If I need to go to hotter plug, what would you recommend for this engine?