Not sure if you're still on the subject of headers...I put this on my outback. I had just 2.25" Cat back with just a resonator in the middle and no muffler. It sounded pretty good, once I put that header on...holy crap...way deeper and has that Subie rumble. It's not loud at all, surprisingly...with the 5 gallon bucket of a muffler removed. But, I left the stock cat section in, my friend has the same setup on his RS but with a high flow cat...it makes it very very raspy. Also, I have an EJ18 block sitting in my garage, dual port, and the header fit on it just fine. The block is from a 1993 Imp.
Those headers are pretty good quality for the price. Even came with header gaskets and header to cat section gaskets and new bolts. Just be careful if you header wrap it, like I did because the header was 3/4 too narrow (might have been from shipping) and I wrapped all three of the pipes (where the passenger side comes next to the 2 driver's header pipes) and it didn't let me spread it. Undid the wrap, worked just fine.