2 plunger or 3 plunger

[JimT]

Quickserve information regarding the fuel pump (It's a free account and has 99% of the info you need to maintain and rebuild your engine):
https://quickserve.cummins.com/qs3/pubsy...08436.html
https://quickserve.cummins.com/qs3/pubsy...07962.html

Video playlist for inspection/install:
https://www.youtube.com/playlist?list=PL...xm_LtX_PCM

Other then an additional cylinder and 4 extra bolts, the pumps and procedures are functionally identical.

What YOU really need to determine is whether the barrels, plungers and tappets have been replaced. The ceramic plungers are a dead giveaway and a major weak point. However even the newer steel plungers and other parts can still be a problem. The ceramic plunger breaking was bad, but the metal debris from the tappets and cam can occur regardless of plunger type.

On a 2250 you're looking at a few hundred bucks and about an hour of your time to do the job and ensure you don't have a catastrophic failure any time soon. Some 2350's don't have replacement parts available so you need to look up your engine in quickserve and find out exactly which parts you need. Consensus is that you should replace the guts every 400,000 miles or roughly 8000 hours. Most failures seem to occur somewhere between 400,000-450,000 miles, so replace prior to that.

Personally, from my experience, I would open up the pump head at least once a year to inspect it. Worst case you waste a little time and replace a gasket, best case you catch a failure in progress before it actually causes major damage.