Im putting my motor back together on my S4 na, Removing all emissions. Can I swap the center iron with an s5 na to avoid having to block off the egr on the s4 one?

 

are the primary port runners (at the LIM mating surface) the same shape between the two? I know on the s5 turbo they are not.

 

they actually do look the same but I wasnt 100% sure

 

The intake port locations (and sizes) on the irons are the same for S4 & S5 NAs, but the ports used for emissions (below the intake ports) are arranged differently. Offhand, I think the S5 has the port air path located on the center iron, while S4s have 2 on the front & rear irons. Of course, if emissions aren't a concern, then that part doesn't really matter.

 

Thanks a lot.