Does the engine have a radical cam and Big cfm carb? Sounds like maybe it has excessive rich condition with too much timing. Holley carb ? If so, the power valve may be open all the time. Single plane manifolds may cause fuel puddling. Need a little more info on your engine component combination to make a informed diagnosis.
I would look at the carb.obviously the timing must be close enough that it will start and stay running,but It sounds to me like you may be running it lean. This will make your headers turn colour in a hurry, not to mention the havoc it could be doing to your engine. Dont run it to long until you verify your timing and your carb sizing.
The problem is the engine is running way to lean. If This condition is not corrected you will damage a lot of expensive parts. I had a motorcycle once that someone had set up too lean and it did the same thing. Actualy ruined the chrome on the pipes.
retarded timing can and will cause red hot exhaust-I recommend referring to some sort of service manual to get an idea of the baseline timing required for your engine. If I remember right, olds motors do take quite a bit. You can also get a relative idea of rich/lean, by introducing fuel or extra air when running it in the stall by using propane, carb spray, or opening the pcv valve hose.