JR- if you have a 6-71 or 8V-71, they have dry liners. This is one of the reasons I got my bus with the 8V-71 so it couldn't leak from the wet cylinder liners.
The only other dry cylinder liner engines, or no liners I know of are the Caterpillar 3208, 3116/3126/C7, Cummins ISB, Mercedes-Benz Series 900.
All other engines have wet liners that you should be diligent on testing the coolant for acidity. A coolant filter is also good. Good Luck, TomC