Vary few diesels engines are two stroke, Most are four stroke, and all are going to be four stroke because the old two stroke wont meet the new EPA requirements. The Power Stroke or Cumming B-model, four stroke.
4-71s were used a lot in medium duty trucks, it came in sizes from 1-71 to 16V71. they quit building any of the Detroit Diesel two stroke engines a few years ago, so they are now a collectors item.
I have not had any first hand experience with the Duramax, so I can't say about that one, but my self I would NEVER own a Cumming powered anything. the Navistar Power Stroke, yes, good engine, holds up well. But for we I will stick with gas in my pickups, I don't work them enough to justify the price of a diesel.
For use in a Classic truck, I would stick with a Detroit Diesel, depending on the size of the truck. for a pickup a 4-53 or 4-71 will work just great.
For the record, I just picked up one of the "Worst Diesel Engines Ever" (not my words, but said by many folks that worked on them back when)
GMC Toro-Flow DH478 V6 , I just wanted it for to say I have one, don't know what I'm going to do with it, display engine or put it in a pickup?
