I just came across these new headerz.
PPE Engineering Long tube race headers w/ true merge collectors & true equal length primaries
23whp 19tq on Nismo 370z - stock nismo exhaust
*sounds like a low quality sound clip
YouTube - 370dyno2.mp4
I think these will go well with the new Injen Nismo tuned intakes. I'm going to order me a set in a few weeks. They claim +13whp on the nismo
2010 Nissan Nismo 370z Injen SP1990P SP1990BLK +13 whp R&D Dyno Session2 on Vimeo