Re-read the posts above. A guarantee is only as good as the company offering it, and most of the time on a high performance piece, the company is going to try and fight you and say that you did something wrong to cause the failure. Do a search here on crate engines and read what others have experienced.
When your local (or not) machinist hand builds an engine, his reputation and possibly his money is on the line. He should take the time to do things right and not cut any corners. I don't think that can be said about the guys who are assembling crate engines.
That being said, my buddy has a 360/380 crate engine in his Demon and he beats on it regularly. Is he one of the lucky ones?!?
