I recently bought a streetport racing beat exhaust from my friend, the dual tubes back to one muffler. I thought I was just buying from after the header to the muffler but he gave me the header also. So can I get the 12a header to fit on my 13b? I know you can get the 13b header to fit on a 12a by ovalling out the holes so can it work the other way?

 

You have to cut the flange in half, add metal and then reweld it.

Best to sale it and buy the correct one, or trade with someone

 

I'm thinking of using a 13b pace-crapper header on a 12a possibly. Its coming off a 13b soon, and if all it takes is a little ovaling to fit and nothing else, that may be worth it...