Dont know what year the F350 is, but there was a class action suit or recall on some model years with the 5.9 or 6.2 diesels. The head bolts would stretch and cause the gaskets to leak.

My buddy found this out while on a out of state boating trip. $4200 later he was back on the road. Hose the out of stater!!

He checked into it when he got home and Ford did Reimburse him for the whole amount. It took him a year or so to get the money.

Boy, thats another hit for your buddy. Even if Ford does cover the head gaskets and new Arp bolts thats part of the fix.