Finally got the engine in my challenger(new engine). And noticed that I had 3 header tubes glowing red. It was previously on a break in stand with some cheap 1 3/4 headers and mp elec. dist. Now its in the car with 2 super comps. and msd pro billet and 6al. When it was on the stand I never noticed any probablems with "glowing" header tubes. Is my timing off? Or just running lean? Its a 500ci with a 6bbl set up. This may be a stupid question but how can i adjust the mixture? The one screw i've found on the center carb doestn' do anything when turned.