JohnnyHNs,
I agree with bak 189 use a breaker bar instead of an impact. It gives you a better "feel" as to if something is wrong, like loctite. I don't do much engine work but I never use an impact on one. And again I agree with bak 189, build ourself a nice bench and put the engine on it and not the floor.
I really admire you for being so "vertically integrated" that is business speak for doing everything yourself!
Rex
When you learn by experience the test comes first and the lesson comes afterward.