Originally Posted by mjmarovi
Don't think any of the OEM internals have been stress tested, which is why I'm interested to see the longevity of the 700 WHP cars (single & TT setups). I would hope that anyone running that kind of power is regularly checking the compression and looking for early warning signs of internal failure. Obviously buying forged parts you're buying to a specific spec... If you wanan make an unscientific comparison, Dzenno's car with RBs + Meth put down ~555 WHP, so that's ~50 WHP gain with headwork over an untouched motor with RBs + Meth.
I'm sure if you contacted VAC about their N54 heads, they could give you something more scientific (flow bench numbers, etc). "