Last night I was running across the lake cruising at around 3500 rpms and noticed my headers glowing pretty good. They weren't glowing to terribly bad but they where still glowing and It's never done this before. It's a 350 with a demon carb. It's been doing pretty good for me sense Iv bout it and just happened to notice this and figure I better go ahead an address it before it could lead to something worse. From the glowin headers I figured it might be running a little to lean. Where should I start to try and figure it out.