Fresh rebuild on a '76 400: flat-top pistons, Lunati cam, Edelbrock manifold & 600 cfm carb, short headers & turbo mufflers.
After initial firing & the usual ignition timing & carb tweaking, engine ran for about 20 minutes at 2000rpm with no smoke or apparent problems. It did get pretty warm, and popped the radiator cap on shutdown...I think I didn't have enough radiator or fan.
Upon removal of the headers, I noticed that the entire exhaust path, all ports, was coated with a fine black soot. Plugs were the same. To me, this says rich fuel condition, but in the past I've always noticed some smoke or fuel smell.
Any other thoughts?
