i have a 2001 kenworth t300 with a isc 300 8.3 cummins, is sad to make 300hp at 2000rpms. the truck has a 2500gallon septic tank on it and is 18,750 pounds unloaded and over 30,000 loaded. i have a eaton 6speed manual behind the cummins with 4:11 rear gears. I would like more power. talked to kenworth they want 400 to turn it up and cant tell me what kinda power it will pick up or if it will get smokey. if any of you know anything about the 8.3l motors speak up and post some info thanks fit now my big iusse is on the high way loaded or taking off loaded trying to get up to speed. i can hit a big hill running 75-80 and top the hill at 60 and it takes about as long as a train to get up to speed unloaded its a great truck it will not even slow up when you hit a hill unloaded but loaded it wants to die

 

Do you know what kind of fuel system it has? VP-44 injector pump like a freightshaker? If so, we may be able to point you in the right direction. Were not all that familiar with the bigger trucks.

$400 to "turn it up" is cheap but I would definitely want to know what they are giving you for your money. If they cant give you details, Id keep looking for someone that can and will. I think I would talk to Cummins directly.

 

ill look on the tag to make sure but i think its a vp-44. i dont think its look like a p pump

 

Definitely contact a Cummins dealer. I used to work with fire trucks and I know there was a 330 and 360 HP rating. The 360 was allowed for fire service only though.