Check Out This Badassary...

The High School I attended had (and I am assuming still has) a slant 6 setup similar to this for backup power. I never got to spend a lot of time looking at all the details of it but was never able to find any markings indicating who made it or at least who made the generator portion.
My HS had the boiler system that was powered by a slant. I never saw it myself but my brother who worked for maintenance there had the responsibility of keeping it up/ being as how he drove a Duster with a slant at the time I'm sure he knew what he was looking at