Looks like you are making some good power according to that scan. I would recommend that you richen it up a little when you drop pulley sizes though, even if you aren't seeing knock.
Stock exhaust manifolds will make more power than all the people one here that tell you, "you need headers for your stock pulley car, or it will blow up ohhhh emmmmm geeee."
We have a local guy running meth injection through the blower on a 3.2 pulley with 91 octane and no knock. He switched to E85 a month ago, and dropped to a 2.8 pulley. On stock manifolds. No knock.
I do have question for you. I'm also after a nice, quiet exhaust that flows well. Is it better to use two smaller resonators with a pipe in between like you did, or would one big resonator be better?