my stroke has to go back to the shop, its thier fault

Sorry to hear this sort of thing but i've been there and if one isn't schooled up on his ability to do it himself ( like me) he is at the mercy of these professionals. It would be nice if people would stand behind their work as i do in my business but you also have to consider that when they build a performance motor what do you think people are going to do with it when they take it away? I would expect them to warranty defective parts unless they were used or stressed beyond they're ability to performe, but the manufacturer should assume some responsiblitiy also. Hope this works out for you to your advantage.