Need help identifying Cummins engine

[Tony Ingram]

I've picked up a 61' G model a few years ago from the original owner. He told me it had a 250 Cummins in it. This truck had the original plates on it with a 62' registration tag, original title, it was pretty much a time capsule. I have tinkered on Mack engines but have little knowledge of Cummins. It has a turbo on it and a tag on the fuel pump says NT-280. There's another tag on the drive pump that says NH 250. I was under the understanding that a 250 Cummins didn't have a turbo and I'm assuming you could've put one on at a later time but he seemed to have kept the truck all original. Can anybody with any knowledge of Cummins give me any tips how to better ID the engine? I've got pics of the engine and tags but can't upload any. The site tells me the pics are over 14mb. I'm not computer saavy. 

[66dc75]

NH 250 was non turbo and did not have external injector lines, just a line to the front head and a return from the rear.

[hurstscrambler]

I don't know much about them at all, but I have been told that it was common that a turbo be added as well as pump and timing changes made.  Maybe that is what you have.  Andy

[j hancock]

It seems that if you find the "CPL" number on the engine tag, that will greatly assist in identifying what you have.  With a CPL, Glenn A. can tell you what it is.

There were variations but Mack G-73 "seemed" to be built with NH-220 and NH-250 engines, the G-77 built with NHS and NHRS engines, G-733 with NT- 280 and the G-773 had NTC/NRT 335 engines.

[Tony Ingram]

Thanks for all of the info fellas!