My son had his replaced he bought his injectors 50hp from DDP I think they were about 3grand + install at Cal Pac Cummins. He got a break on the install I really dont know much that cost. But I will tell you one thing that Mod made the truck run like a striped *** ape and they must be pretty fast because San Diego Zoo dont even have one of those and National Geo cant get a picture. All BS aside it does run allot better if that is what your into. Mileage well never know because he cant keep his foot out of it and it means that he would have to do some math.