I'm guessing they do heavily urge against it, but sometimes customers insist.
Why on earth would you put a 150+HP motor in a set of cases designed for a 40HP motor?
I understand that 300' guys are trying to save weight, but it's just stupid to think those cases will hold up.
I've seen what 120+HP motors do to cases when something lets go.
I've also seen what happens to a set of billet cases when a crank breaks in half. I'll take billet.