This is probably a super stupid question,but if your going to be getting into the motor anyways, why wouldn't you go ahead and notch the pistons so it would work? Can this be even be done? I understand you'd be tearing down the motor completely to get to the pistons and that's a lot more work. Would it be worth the work or not?
There's a lot more money involved with doing that. He should be able to save the expense of a full motor rebuild plus machine work, and just get another cam for only the cost of the cam/possibly a custom grind. He'd then only be out the cost of the cam.