The 451 is just a smaller packaged 440. They will rev.
On the output - given the broken part(s), you may still potentially have an issue. T&D is a very good rocker - but bad harmonics can break the best. I didn't watch the video -but I would add one can tell a lot by the sound and I'd put a lot of faith in RAMM's ear. I don't put much faith in dynos for a lot of reasons. Stick the engine in the car, weigh the car, and run the car down the 1/4. Then you'll know for sure.