OK, one more question for you guys with all the knowledge. When a truck is stated as having 450 hp can go to 550, is that accomplished by the computer chip? Also, I realize that you should not get a truck that is too weak or too powerful for what you're pulling to save gas as well as engine wear. How do you accomplish this properly? Should you tune to the high or low end of the approx 450-550 window. Any tidbits of wisdom would be appreciated.

Most of that is done with the computer.


My mechanic recommends for anything over about 600,000 miles to leave it alone unless you want to rebuild the engine. With that much wear changing the power drastically will cause an other wise solid engine to wear faster and require an over haul sooner than it would have had the power been left alone. HOW EVER if thats what you want to do he recommends doing an over haul running it for 100,000 to get every thing settled in good and then turning the power up.

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It's crazy even considering 600,000 miles. Is that normal engine life? How do I decide where in that 450-550 hp range I want the truck to be tuned when I get it? How do I know what size loads I'm going to be carrying for the optimal tune? Should I just have it tuned high, or can this be bad too?

The only way to spec your truck properly, is to know what kind of hauling you will be doing. For example, if you pull a lot of heavy haul/OD, then you probably want the motor turned up all the way. Do you run all 48 states, or do you just run in a region? Do you pull a skateboard, or are you a tank yanker?
Once you have got time under your belt, and are ready to make the jump to being an O/O, then you will have the answers to these questions. And then you can spec the truck to accomplish the job you need it to do.

And 600k is on the low side for a rebuild; properly mantained, most engines should be able to pass that mileage.

Much more important than the specific power rating is the torque rating that accompanies it. And to have a higher torque rating, you have to have the rest of the drivetrain able to handle the higher torque, or you can easily destroy parts of the drivetrain. From the clutch, to the transmission, the U-joints in the driveshafts, the rear end gears, even the springs and axles, all have to be specced for the higher torque rating that comes with the higher hp. And you also need to look at the front end, and make sure that your radiator and coolling system can handle the higher hp and the associated heat increase.

Much more to the issue than just cranking up the horsepower. Do it wrong, and you will wipe out a whole load of expensive parts.

Troof! I've seen it first hand!

So this means I can comfortably get a used truck with 300k+ on it (with good maintenance of course)? What would a good yearly mileage be? Thanks for the tip on torque. I forget that's very important when it gets to these huge beasts. If I'm looking at a used truck, where is the best location for an inspection, a dealer or local shop? About how much would one run? Thanks again, sorry for being a pain.

At the current time, a truck with 300k on it is going to be about a 2004 to early 2005 model, based on most trucks accumulating 120k miles per year. Expect to pay 35+k on the lower end, and up to 60k+ on the higher end of the scale.

As for inspections, the dealer will provide one on the truck, but I greatly prefer to have a truck taken out and a couple of inspections done independently. One, a complete chassis dyno run by the engine manufacturers rep. This included putting the fully instrumented truck on a chassis dyno, and running it. They will also download the computer and ECM unit and compare the results with what the trucks computer says it i supposed to put out.

Secondly, I like to have a complete annual inspection done by a mechanic independent of the dealership. He goes completely through the truck, looks it over and determines what needs to be fixed, and what lifespan are left in components like brakes and other wearing parts.

Thirdly, I like to have a good suspension guy go through the underpinnings of the truck, and determine if there is any wear or problems in the suspension and rear ends.

To have all these done will probebly set you back 300-500 dollars. However, by having it done yourself, you can use the info as bargaining chips when you go face to face with the salesman. I obviously don;t recommend doing this with every truck you look at, but if you can get the selection process down to no more than one or two trucks, even if you pay for one of thses on a truck you don;t buy, it will save you money in the long run. And at worst, you are looking at 2-3% of the purchase price for this insurance.

I won;t get into any lomg winded speeches about gaining experience, but based on what I see here, are you experienced enough to go into business for yourself at this time? If not, then you might want to do some more reading of the site and find advice that has been given in the past to others in your situation. You need some time (2-3 years) to learn the business before setting out on your own. if not, all you are doing is setting up a deal for someone else to buy your trucks after you go broke with it. My 02.

if the engine is rated at 470 HP and was turned down to 370 HP by the company-chances are you'll be ok to put it back to it's original HP rating.as for "pumping" one up after it's got 600K on it at it's "designed power rating" and then you try to get even more---yes you're asking for trouble. kinda like putting nitrous oxide on a tired 350 Chevy,it'll haul ##### for a short time untill it grenades,and truck motors aint cheap!

Thanks for the info Burky and javelin.

You are absolutely right Burky, I don't currently have the experience. That's the beauty of being able to ask questions on this forum. I can gain SOME of that experience from those of you that have it. My main reason for being on here is to try and make the right decision on what could possibly be my next career. I don't want to go into it blind like I did on my current career.

Thank you once again for the tips.