Hi Robert,
I've seen some cut out sheets of foil backed insulation to wrap around the botom of intakes, carbs, and fuel bowls...secured by zip ties, or wire, etc.... after a few heat cycles, the cloth will get more brittle...
I have seen these on many cars, but I'm not sure in my own mind, completely legal, so I stick with other stuff attached to the header...which is unrestricted in design...to a degree... May be a good thing to discuss here to get opinions. I'd love to wrap my intake with insulation... I'm just not sure I can. I need some lawyers advice on this one.

David