Cummins,Detroit,or Mack MP8?

I'm getting back into the O/O trucking after a long break. I'm trying to catch up on the new trucks and have some questions about Cummins, if you don't mind.

Besides the fuel pump issue (which I understand is not as bad on the 2350 vs the 2250) what other issues does a used truck buyer need to look out for?

As to the fuel pump issue, my understanding is that they should be rebuilt every 350-400k miles before something bad happens. What does this usually cost?

Lastly, is there any fuel mileage advantage of an 871 vs 2350 (all else being equal - tranny, gearing, load, etc)?

Any reliability advantages for the 871 vs 2350?

Thanks in advance.

 

Wow, that's very impressive [hat tip]. How much did it end up costing you? How much diesel mechanic experience did you have beforehand? Thanks

 

Cummins cm2350 carbon packing issues causing cylinder polishing, liners drop often on 3,5,6 cylinders. And the ceramic 3 piston fuel pump is just garbage. Replace with old 2 piston fuel pump, fuel actuators have no factory wear indication or test specs, don't buy rebuilt ones. The cams like to eat themselves, at 500,000 if you follow factory overhead service. More oil pressure is a good thing, shim the oil pump a bit. There are videos on youtube.

 

I am not a Cummins specialist. You need to go to rwze and ask him. I know more about DD15.... Here is one video from mechanic about isx.