Well i bought my 2005 6.0 with a 120,000 miles on it 3 months ago . The dealer i bought it from said it had the headstuds done , and egr delete , which the delete i can clearly see . But now when i drive the truck its eating a gallon of coolant , basically boiling it out the reservoir up top. I took it to the radiator shop and they took a fuse out so the motor wouldn't start but it would crank the starter and he filled the reservoir to the top , when he cranked it pushed water out the reservoir . I'm assuming headgasket gone bad ? idk its going in the shop monday and the head diesel mechanic will tell me but what are yalls thoughts ? if i have to get new headgaskets or studs which gaskets ? stock? Should i get upgraded injectors from warren diesel while i got the truck torn apart because it has 120,000 miles on it ?