The Big Cam Cummins series predates the N14. Both were/are available without electronic controls of any kind. I think, (some help here) the N14 came with the Cummins version of the Jake Brake built right into the engine. The N14 might be a little bit taller than the older Big Cam equipped with a Jake Brake. Not sure. Been too long.
Anyhow, both the mechanical versions can be hopped up using either used or new inexpensive, (relative speaking) factory parts. Older 2 stroke Detroit expertise may be dying off....however, out here in SW Oregon, the older Cummins are king. Easy to find a mechanic. I was going to update to a Big Cam Cummins in my old Crown Supercoach.
It is all about costs, availability and maintenance ease. Nothing wrong with the older Big Cam Cummins. Power ratings all the way to 475/1450 are easily made going $cheap$. Another advantage is that the mills have zero $electronical$ stuff to fail. Try www.pittsburgfuelinjection.net
They may still have a site. HB of CJ (old coot) hope this helps.