Your engine should have had a factory installed heat shield over the solenoid as mine did. I eliminated mine in favor of a wrap which covers both the solenoid and the starter and is secured with velcro. I purchased mine from O'Reilly's and it was a tad wide so it was modified for a better fit.
Since the battery in my Vette is mounted behind the drivers seat it came from the factory with 0 gauge battery cables which in my opinion you should be running as your engine compartment is small and if your hood sides are not louvered you're going to continue to have heat related problems. In the summertime you might want to consider running without the hood sides.