350 and 370 for emergency vehicles on highway and motorhomes too. Don't think it's outta line. At 370 it's still not maxed out and blowing smoke either. Did I read right there is no ambient air sensor on your motor? Pretty sure it needs it to calculate egts. They will defuel if it calculates high egts on a hard pull. You almost have to drive it and monitor atmospheric pressure sensor. My bad one gave me fits to diagnose until I saw it live. One mile it was fine next it wasn't. You can unplug it and it will read just above sea level. Light will come on but if you notice more power and consistent power that's your answer.