I just picked up a 4-1 Megan Racing header for GSR with the 2.5" collector. Looking at it, I do not see how a standard 2.5" donut gasket would fit on this header, as the collector flange (2-bolt) has been welded at an angle on the pipe, making a flat-backed donut that sits perpendicular to the pipe (90 degrees) an impossible fit, as the flange would angle away from the gasket when seated. Can anyone verify if their GSR header (any brand ok) has an angled flange or if the flange should be at a 90-degree angle to the collector pipe? Please see pics below...any help is appreciated.

 

i just got my header in the mail today (megan 4-1) and i have the same issue. did yours fit your car at all?

 

eesh. i guess the gasket will have to compensate for that angled flange.