09-11 OEM headers vs Updated OEM headers
 

I just got my HFC from Fast Intentions and they made for the 2010 oem headers.

My question is could I purchase the updated OEM headers and bolt it on the FI HFC or it won't fit?

I absolutely want to use these HFC as I paid a lot for them and I do not want any rasp.

The newer headers will fit. Unless you are doing the install yourself, with friends, or have a hook up on labor, it can be very expensive and might not be worth it depending on price.

Seconding what Panda said. Just realize that chasing NA power is expensive, in terms of both time and money. The amount of performance you'd gain from swapping between headers made in '10 and headers made a few years later is pretty minimal. If you want to do it, go for it, they'll absolutely work.

If I was gonna change out the OEM headers w/test pipes I would have gone long tubes and done the job once. IMO

Yeah from everything i've read / watched removing the factory exhaust manifolds is a bear. If you're going to swap manifolds go to a shorty or longtube header. Get all that performance at once and make the job easier on yourself.

Hell, if you're doing headers, you might as well do cams while you're in there

I tend to agree with this reasoning but the local law enforcement would harass me more having test pipes/long tube headers than a turbo kit probably. They don't like to hear the typical straight pipe sound. The turbo kit would actually absorb some noise.

I want to keep the build nice and clean for now and really don't like the test pipe/LTH noise. Too much hiss, rasp, can noise for me. I like the stock tone but I want it as unrestricted as possible without ruining it.

Not to mention; the design went from an equal length to an unequal length. While I'm sure Nissan had their reasons, sounds like it would be a lot of trouble just to reduce performance.