So the stock header on our 09 cracked, I got an 07 replacement but the diameter is larger so it doesn't fit the mid pipe and it looks like the flange is larger than stock also?

I was told we could use the 07 - 09 header but apparently that isn't so.

I would think it should fit the cylinder, any ideas on how to make this work, and how it might run with a larger header diameter?

as far as i know they are identical, are you sure its an 07 and not an 06 or lower?

I was told it was an 07, I looked on the parts fiche, they do have different part numbers,

09 - 5xc-14611-R0-00
07/08 - 5xc-14611-20-00

there is the possibilty I was given the wrong part, I measured the ID of the header and it is approx 40mm, the replacement one is approx 43 - 44mm. does that sound like a 450 header?

Edited by steve_97060, 05 May 2012 - 07:25 PM.

I was going to say it sounds like you got a 450 header if the flange is bigger. I know they didn't change the size of the exhaust port on the head during the years.