You guys have been told wrong. The heads are not prone to blowing gaskets, and the exhaust system has little or nothing to do with it. Any iron block/alulminum head combination is going to have headgasket issues, and forced induction makes it worse. Most SC motors went 100K miles without headgasket issues, but in the end it's going to happen unless you use MLS headgaskets (properly) in which case it will become a non-issue from at least a mechanical standpoint.
Other than the fact that iron block and aluminum head combinations are toxic in the first place, the main reason that most SC headgaskets failed is because of cooling system and fuel system maintenance issues and tuning. The factory tune is very aggressive and leaves little margin for error and NO room for modifications.