The best way to keep a 6.0 out of the shop for repairs is to take it into the shop for maintance. Don't drive it like a grandma. Adding an exhaust and tuner won't make it anymore reliable. The only thing I would suggest is deleting the EGR system and leave it at that. My truck always gets serviced and the engine has been trouble free till 60K when the EGR cooler broke but that was kinda self inflicted. What I suggest doing is take it to the dealer ask to have the engine pulled out of the truck and have them do all the updates on the engine and while it's out ask if they will put ARP headstuds in it if you supply the studs. Oh and have it done under warranty.