You're right RRR, but there is a difference between 600hp and 900hp hammering a block for 8, 9 and 10 seconds then it is having it do it all day.
I do it, and im still doing it, but im not putting that motor in a speedway car or boat and seeing if it can do it longer than a minute.
I also think the north of 600hp rule is being overlooked and misunderstood, no one said it can't, it can, living and under the use of here is a 600hp motor have fun... That's the difference