Muddog;
A lot of people do run there engines on a buck or stand just to make sure they run and don't leak anything.
If you will go to cctskit.com and look under our technology you will see one of the dyno's we use. That one is a 600 hp one and I also have a 1200hp Dyno. I can put them together and get 1800hp of load on the engines.
We also have a 400KW load bank and can have Valley come over with there 500KW load bank and can run 900KW of load on a gen set if needed.
There are a few shops around the U.S that have load cells to Dyno there engine. Delaney&Ahlf, Valley, Jasper, Gem Equipment come to mind. I know there ere others out there with the ability to Dyno an engine.
Hope that helps
Don