choosing a header for my Z and how much whp I can get

SouthArk370Z

Back in The Good Old Days of big blocks, dual quads, &c, it was a pretty safe bet that the bigger your exhaust pipes, the better the performance. Not quite that simple, but it's my post.

Nowadays engines, especially hipo engines like the VQ, are high-strung, sensitive, intricate works of high-precision engineering, that don't always do better with bigger. You have to reach a balance between intake, engine, and exhaust.
You can't just throw the best parts together and expect to get the best system. You need parts that play well together.

That said, keep asking questions. The more you know, the better your decisions will be.

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