Dave told me to use vice grips on the stubborn bolt as I can put a helicoil in if needed. I was thinking to try my impact wrench on it, maybe that'll knock it free?
Don’t use an impact. Case is aluminum and bolt is steel. The case will break before the bolt will. Heat it with a propane torch and let it cool. If it still doesn’t budge, then cut it off flush with the case lid and remove the lid.
Then drill it out. If case threads are damaged, you can easily tap threads into the case.
