I remember handling really hot spark plugs with my bare hands..... Haha. But that reminds me, the hyper pistons dont expand very much when they get hot due to the silicone in them, compared to the cast aluminum which are the same size ( 3.55 ish ). The pistons did have a little movement after installed and rings were tight with about a 1/16 gap ish. But they wouldn't sell bunk pistons right?