Don’t take my word for it ... for the last 10 years or so FelPRO gaskets have had a disclaimer on their boxes to the effect that “due to piss poor machining we can’t guarantee that anything will fit a Chevy”
Chevy has never made anything that was not under engineered and over priced. What was the year model of the great six banger that had the exhaust and head cast together. POS.