Thoes boxes are your intake manifold and heat is a bad thing, this is why LET sells phenolic intake gaskets to limit heat soaking into the box. I did black to assist appearance and the little gain from black body radiation. The lower half is not painted.

I also removed the hood insulation to allow better cooling of the motor and also allow some of the engine sounds to leak out a bit, being a squirrel at heart.

Check Let for a photo of the gaskets, a simple installation to do, Woody