450ST CM2250 Help

[Waterloo]

Everything JimT said, gearing will be your main culprit in power loss, the 450st will work fine in your application. If you are going to purchase, see if you can pop the top on the motor and exam the camshaft and rollers. Also do a forced regen and see what the numbers are in regards to hg. That will tell you quite a bit, these emission systems can get very expensive if you decide to purchase and keep.

Myself, if the truck checks out, and you are not running around out in California, I would kill the beast and eliminate the mandate.

What is the truck mileage and what gear ratio in the rear ends, also which transmission? Private party or fleet truck? The fleets normally change the oil every 50,000 miles, the motor is normally shot by the time they sell it. These are 500,000 mile motors and either dispose of the truck or in frame the motor. Rare to see an abused fleet truck make it to 600,000 miles nowadays.