5.9 CUMMINS
It is easy and cheap to get 300 or more hp out of this motor. All you need to do is put marine injectors and change the plate in the pump so the rack can put more more fuel to them. Same turbo same air cleaner and it will be fun to drive. It should get 8-10 mpg. I have done done many of these. An 8.3 can also be turned up easy.