Do you know of anybody that has switched over to running an electric fan or fans on their CTD yet? I think that will be another project that I will put on my list for spring or summer. It's gotta be better than swinging that big fan around. I used to take the fan right off of my gasser trucks in the winter for a couple of months at a time. They are alot quieter and and have better throttle response without a fan in the winter plus they heat up better, as long as you don't have too much city stop and go driving. I believe the Derale fan company sells fans that have a built in adjustable thermostat for their fans now but I know for sure that Derale sells a kit with a coolant sensor and a potentiometer [$44.95] to adjust the temp that the electric fan kicks on at [ like the one that I have on my race car]. Actually for the price that is a cheap fix for any car with an electric fan that has "issues" and doesn't want to work anymore because of a wiring or sensor problem.

Do they have a wet sleeve design so you can just change them out? I think Detroits are like that?

Nope the B series have a solid block, That is why they are internally balanced so you can bore a single cylinder up to .040 over and run an over sized piston in 1 or several holes. Or you can bore it out over sized and drysleeve it back to stock size.