There must be someone out there that knows something about these marine engines.

I dont know the exact specs but one of the main reasons they had such higher HP was the fact that they have a unlimited source of cold water to keep things in check. I know they used them in military Tanks as well.

I have one of those marine engines.  The company that built these is in Daytona Florida but I can't think of the name.   The guy I bought it from said it was 950 hp originally with two turbos but took one turbo off and derated pump to 750 hp.  The reason they could crank the power was because of the unlimited cool water as the last post stated

Daytona Marine (DME-900) was what was in our Shrimpboat 

https://www.bigmacktrucks.com/topic/50389-truck-to-boat-engine-swap/?tab=comments#comment-374249

https://www.bigmacktrucks.com/topic/34624-mack-–-scania-cooperation/?tab=comments#comment-231636

I had a friend put a marine engine in a superliner, had to come up with some jakes and rework the pump for variable speed governor.