Red exhaust manifolds on a dark night are common. I'd bet if you run her a while and quickly raise the hood both would be red.
Exhaust heat can be helped by increasing the timing. Does the computer you installed control the dist?
If not then I'd be retiming the engine. If it DOES control the timing as well as the mixture there is little you can do.
In short most exhaust manifolds on most vehicles are red at all times on the hiway... one just doesn't get to look at them.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist