Dave, I had heard of the aluminum head problems on the 6 cyl. My opinion is that aluminum heads on diesels are a no no. I tell all of my clients to NEVER let a Diesel overheat...especially ones with alum. heads. Thanks for the info on the studder at startup. I have left the glows on longer and it starts better. The owner DOES drive it like He stole it... I will caution him though to wait untill it is up to temp before standing on it. Chris