Well where I worked we did have some of the Cat Gensets, the old school D379, D398, and one of the D399 16 cylinder version. As for the Cummins K-50 worked on and around it's little brother in loader applications, originally called KT 1150 that was renamed the K-19 when they went to liters from cubic inches. Also rebuilt a naturally aspirated Cummins 1710 in a genset that had spun a cam bearing. Last two gensets I worked on were a bit smaller a Perkins 4 cylinder powered on and a 3-53 Detroit. Both these were almost scraped as both engines had been poorly stored letting water get in exhaust. Managment just doesn't seem to understand how to properly store things. Runs one day they unhook them and just stick out back till they need them again.