3 cylinder fuel pump info

[Hammerhead]

I don't know my @$$ from a hole in the ground on these three cylinder pumps other than the horror stories I've read here and heard.
The way I read, understood, & took Uni's reply to your question was that "Yes the plungers are the same in both 2 & 3 cyl pumps."
Without further clarification if I wanted to rebuild a three cyl for a spare, I'd pop the head and pull a plunger. I'd take that plunger and a good set of calipers and go on down to my local Cummins dealer and I'd ask for a two cyl plunger by part number and measure them both side by side six ways from Sunday right there at the parts counter...trust me, no manufacture is immune to being frugal and using the same internal parts across different components to save manufacturing costs, they just give them different part numbers to hide the fact. When you really start comparing parts, you start to see the real amount of interchangeability there is.