I have often thought about having a "spare" 6.2 engine just in case. Are these plentiful? I admit that I haven't really looked into the issue. Would a spare engine go bad just sitting in my shop for a long time? I wonder if it would be cost effective to get a non-functional engine and rebuilding it. I have never done this type of work so I don't know what I would be getting into. Anyone have thoughts on this idea???