Every packaged I've bought said it was oil/gas resistant once cured. I've repaired sever gas tanks over the years and never had an issue.
But that was the reason I said run/thread a plug down the bolt hole then backfill.
Their packaging has said that for as long as I can remember. That's like saying Alexandra Ocasio Cortez is conservative. It's just not true. You can ask any cylinder head porter who does a lot of it. If it worked well, that's what they would use. It's not.
