[Steve Levin]

Something to keep in mind with any engine changes -- they rapidly cost engine life, and typically disproportionately to the amount of extra power generated.

I've worked with the 3.0 litre Cosworths for vintage F1 cars, and the rule of thumb is that for every 1,000 rpm you pull back redline (from, say, 10,000rpm) you double engine life. And the difference in power between 9,000rpm and 10,000rpm is not all that high.

So whilst I don't have a good anecdote about taking a 425hp engine to 560hp, my gut says that, all engineering aside, that a 30% increase in engine power without reworking the engine internals is going to end up being very, very costly.

But that's just me.

Steve