not much for something gutted out like that...about 350-400whp. which honestly, is less than a 500 dollar investment. its deceiving though, you say horsepower but diesels are an entirely different beast, a 600hp diesel typically makes 1500# of torque. if you spun that same diesel to gas motor rpms, the numbers would begin to look a bit more similar...remember, horsepower is just a number in an equation...torque is the actual power the motor makes.