The 444 is a glorified 400 big cam. they hang together as good as any of the nh series. It will run with the 425 cats. If you retro fit a decent after cooler in front of the radiator and take the guts out of the old intercooler, you gain a few more horses! Thats what it is all about.:knight:soapboxI am looking at a truck to purchase that has a 444 Cummins in it. I have heard good and bad on the 444. Does anyone have any experience with this engine good or bad?