[HO455]

Personally that fact that you're planning on that much horsepower with a 6BT changes the whole equation. You're going to be making close to double the torque with a diesel engine than a gasoline engine of similar horsepower would make. Torque is going to be what breaks things in the drivetrain. I would figure out how much torque your expecting to make and then plan your axle, transmission and driveline around that number. Ask Currie or Doug Williams what axle they recommend for 1000 lbft's of torque.

It's easy to think "I'll be fine if I don't put big sticky tires on it" but the reality with making that much torque while running small, hard tires is that those tires lead to unexpected wheel spin in 2nd gear or 4rd gear at speed. Think about having the boost come on in while passing a car on a curve at 55 mph and both rear tires suddenly break loose. At the least you get an eye opening pucker! And in the rain better hope you've got plenty of real estate around you.

My 09 Ram 2500 4x4 had factory wheels and tires on it when I got it and it also had had a bunch of work done to the engine. It was pretty much able to smoke the tires at will at any point below 60 mph which made it not much fun to drive most of the time and scary the rest of the time. That truck tipped the scales at 7200. Which i'm guessing is about 1500 more than your truck weighs.

I ended up spending a couple grand on wheels and tires as I would prefer to accelerate hard and never spin a wheel. Of course shortly after that I destroyed the carrier bearing.