03-19-2012 08:22 PM
A top end overhaul is normally replacement of cylinder heads, injectors, turbo cartridges, water pumps, and cleaning of aftercooler. In-frame overhaul includes all of the top end overhaul components, plus cylinder packs, rod and main bearings, oil pump, and oil cooler. Top end overhauls are generally only required on 3500 and larger engines. Hope that helps.