Were not high in diesels and far as I know we never have been. We have five diesel techs and that's all we work on. The 6.0 is a piece of junk but just fix what's wrong and diag them right and I don't see how you could be higher than anyone else. I've never needed to use a diag sheet but I do fill them out as Ford says we have to use them to diag them right. But most of the time the whole sheet does not need to be done. Like the balloon test. It only needs doing if you have an injector concern. Another one if fuel restriction. It only needs to be done if your fuel pressure drops below spec. And Ford is right, most of the time a TSB does cover the repair and I think they pay great. M time for head gaskets, 8.0 hours for H.P fitting that takes 2.0 hours to do. Life is great if I a get three or four of them in a day.