Just as a "heads up" about headers.
Stock exhaust systems are generally tuned(yes tuned) for mid RPM range power.
Headers can move this power band lower in the RPM range or higher in the RPM range, they don't add power, just move it to where driver wants it, this is done with the length and size of the pipes.
These lengths and sizes create a low pressure at the exhaust ports/valves, at it's lowest pressure is when you get the most power, which will be a specific RPM, just above and below this specific RPM is the "power band" for this header setup.
"Racing" headers read like the power would be moved to the higher RPM range.
Which is great if that's where you want it, but you do lose power in the lower RPM range, i.e. off the line power.
So check the specs, and don't get surprised, lol.