Starter heat issue?
My avatar has a 408 with a mini-starter (I assume that is a mini-starter you have.) The Hooker SuperComp headers (1-3/4") run fairly close to it. This is its 3rd summer and so far, no issues. I'd run it as is if that's a mini-starter.
As for the pinion gear hanging up, you want to get that adjusted out from the crank centerline a hair as you don't want it hanging up.