I did a search on this forum on red hot headers. I wanted to find out the causes. I thought that it was maybe a lean condition. Some said it was lean condition and some said it was a rich condition or can it be both. What is the most likely causes?
Compressing (compression) would also cause heat, when you squeeze the air the molecules would begin to race around in a frenzy causing them to create friction or heat. Kind of like the diesel engine the fuel is burned more by the high compression and assisted by the glow plugs (so the mixture ignites faster) to cause the combustion. Granted he's probably has a stock CR but that would still cause heat, wouldn't it??
Timing being off can cause the headers to glow. Start with the easier stuff first, check then recheck the timing. Check/replace the spark plugs and such. When was the last time the car was tuned up? How old are the O2 sensors?
this may sound stupid but my headers were glowing red when my buddy messed up the firing order on the distribtor. it took a little bit to figure out but 2 plug wires were in the wrong locations on the cap.
Is your smog stuff hooked up? If so, then if it is not working right, it can continously pump air into the exhaust ports, and that causes the unburt fuel to burn in the headers. Like a afterburner effect.
IIRC, the system is designed to only pump that air in the exhaust for a few mins during startup to help warm the O2's. Then it shouldn't run again (I think). Then it just sends air to the cats, or dumps to the atmosphere.