318 hard start when hot

Tried today to take the starter off. Bottom nut came off easy, top bolt is hard to access, and impossible to remove. Tried heat, pb blaster, impact sockets, every tool available, looks like I'll be taking it to a shop. That dude is STUCK. Even living in the rust belt, I have never had a bolt that hard to deal with. It's in such a stupid spot, only way to even get a socket on it is with a swivel and about 2.5 feet of extensions... Have had wheel bearing hub assemblies be easier to remove than this thing.