Is my turbo ok?

I'm getting a 2000 ram 2500 with the cummins. It's got 300k miles and runs beautifully, I'm buying from a friend that meticulously maintains it as it is used to haul cattle daily. Anyway he got a new pickup so I'm buying the old one and I'm worried because I hear 0 turbo whistle unless I'm accelerating hard with a heavy load. I wouldn't be concerned except that I use a different but identical pickup sometimes, that one has about 235k miles, and it's turbo whistles a lot more. Should I be worried about the one I'm buying or is it just likely that the silencer ring has been removed on the louder pickup? That is a possibility because the guy that owns that one has a pretty suped up cummins that is pretty loud so I know he is a fan of a louder pickup.

It's likely the silencer ring is still on that turbo and making it quiet.
Do you know the lift pump fuel pressure?

No I don't know the pressure of the pump, but I know the guy I'm buying it from replaced it 20k miles ago or so. He used it for his cattle hauling business so for the most part anything that usually breaks has been replaced recently. He averages 6k miles a month on it so he kept everything good on it. I just thought it was wierd not to hear a turbo, doesn't help that I'm used to a 7.3 before this one