Well a stock truck hits around 500 pounds of torque. I think you could hit 450 horsepower with the stock heads and cam with a big turbo, headers and exhaust, a good intercooler, and 50 pound injectors with chip (you'll want the 9/11 converter too for better spoolup). This will run around 6k With heads and cam you could definitely go over 450, but then you're putting a lot of stress on the bottom end.