A starter heat shield is a good idea, providing you can get it in. On my engine, one header tube (Hooker headers) is about .010 away from the solonoid. I even had the speed shop (Lopers here in Phoenix) bend the headers as far as they could and it still had hot start problems. Many years ago I installed the Ford solonoid and its been flawless every since. That was an actual Chevy "fix" many years ago. It came out as a TSB for certain large delivery vans with "no start" problems when hot.