To begin with…DD 60 series 11.1 liter was in production before 12.7 which has over ¾ inch longer stroke for more low-end torque.
There been much internal improvement changes for reliability as well better fuel economy.
I too want later to update powering Sojourner so I have check around with DD mechanic that been there since the beginning of series 60. They told me numerous small problems that had to replace with up-date parts. By the way there is narrow & wide type rod’s bearing for both liter versions. All later versions are wide bearing. If I remember him correctly, that early version had rocker’s roller breaking that made of ceramic. That was one of example.
For the most engine for your dollar in today market…12.7 liter are getting highest reliability rating as far as mechanical aspect. Some over 1 million miles which is about 20% greater than others. So being said that mean most of class 8 truck are equips 12.7 series….results are plenty of them in large truck salvage or recycle yard. They usually price less than other brands.
Get serial number from inquire engine to ask full history at DD to help picking a good ones.
Whatever you choose…get full package such as matching computer system and the accessory that you can use.
Perhaps cheaper to buy whole wreck class 8 that came with undamaged aluminum wheel & tires, dash board with electronic screen and so on & e-bay the rest.
Keep this in mind…series 60 12.7 are lower RPM high torque engine than 71 or 92s. So try to go for higher speed (lower numeral ratio) rear drive pumpkin for using with 740 trans. Otherwise lower speed (higher numeral ratio) ones using with B-500 world trans (equips with two overdrive)….would be a…s w e e t…package for a price.
For freebie…low profile oil pan are...n o t...cheap. I’ll let someone more knowledgeable to answers bell-housing & flex-plate question to mate to 740 Trans.
Installed DD 60 into MCI-9http://www.bernhardbus.com/60_series_MC9.htm
All of DD engine sizes except the latest 14 liter.http://www.endurancepower.com/media/CATALOG_DET_WEB.pdf
Sojourn for Christ, Jerry