I have a 2009 aver and just recently got a different muffler put on and took out the third cat and straight piped the car. While the guy I know was working on my car I got to talking with him about how I want to change the headers but people say its cast yada yada. He took a look at the header and said he could easily cut the existing pipe below the flange off and weld a B16 header to our existing flange so wish me luck I'm saving up for a B16 and going to cut and weld and see what happens