I have a 1977 SE 400 6.6 Manual with the stock exhaust and manifolds. I am going to change it to true dual exhaust, and Headers. I am looking for info as to what type of headers work the best? Long tube short?? coated?? size?? , I am going to use magnaflow's. I'm in Canada so some of the prices here are very high here for headers. Hopefully someone with the same car will give me their input. Thx....Kanedit.