360 Tune Up

Wrapping the headers isn’t a bad idea at all. It is a lot of work for a possibility of zero temp effect. But there is a bit of science behind it working.

In the engine compartment, is there much of an escape route for the hot air?
Yes, down and out is pretty wide open. Lots of room. I think there is not enough air flowing through the radiator. Maybe the shroud is restricting it.