Paint inside of valve covers?

I pulled some Magnum valve covers out of the junkyard this weekend, and have a couple questions:

First, should I paint the inside with hi-temp paint, or will regular rustoleum semi-flat black be okay?

Also, because these things were so gunky, I chiseled the long baffle off of one so I could clean under it. Does the valve cover really need a baffle? Can I run it without one?