Just a thought here, comparing power number is meaningless as soon as those numbers don't come from the same Dyno, and if you don't have the stock curve. Its like comparing apples and oranges ...
Maybe that 450 hp one would read about the same as the 250 other one, on the same dyno, maybe the difference in the reality is much thinner than the number would suggest.
The engine, can take a lot, the internals ... sadly not so much, specifically the bearings.
The oiling is also an issue and can lead to major troubles.
Again comparing numbers from various tunes isn't necessarily the best read of what the engine can take, analyzing the failures is a much more pragmatic approach to determine where are the limits
