The 3196's are the exception to the 31xx series curse, they're good engines. The 16's, 26's, and 76's are garbage. My dad had a sea ray with 3116's in it that had 2 engine replacements by the time he managed to unload it. Cat initially tried to blame it on him. He is a lawyer who does civil litigation. He was pissed, he told the rep I do this for a living it's free to me, let's see how this works out for you, and the guy was like do what you gotta do. So he did. The only reason I tell the story is that you actually had to be a lawyer to get CAT to honor the warranty claim back when all these problems first came to light. Once it was happening to 2/3 of them, they couldn't hide anymore. They ended up replacing his engine, and the second time did it again with 1 phone call.
Anyway, unlike the other 3, the 96 is more than just a bigger bore and has way more in common with their larger engines than the other 3 do. I wouldn't mind a 96. I would run from the others. A common problem for all members of the series are design defects in the aftercoolers which results in the engines ingesting saltwater until they're ruined without warning. CAT is on their 3rd or 4th revision to the aftercoolers with superseded part numbers, and they've still never figured out the problem. A brand new aftercooler will do it in +/- 5-10 years. Any decent mechanic will tell you to treat the aftercooler replacement as a maintenance item. Which at $10k a side every few years is a little rich for my blood.
Edited to add: If you're used to detroits, holy $h!t you need to sit down and ponder the difference in parts prices between CAT and detroit, or CAT and any other engine manufacturer for that matter, before buying. Their parts prices are nuts.
