I'm changing my 235 over to a Corvette manifold with a pair of 22" Smithy's. I plan to finish it this weekend. I had a stock muffler on the stock exhaust manifold. The stock muffler was extremely quiet except under heavy load, where it worked its way up to quiet. Due to an ignition problem I blew that muffler up. I was very surprised by the lack of content when I looked at the insides (pic). I think the engine characteristics have a lot to do with the sound as well. My 235 is stock in a 55.1 3100, so it has virtually no compression (7:1?) and a cam that is so conservative it would make Rush Limbaugh feel embarrassed. One of the guys in my local Inliners chapter has a 235 in his 53 with higher compression and a mild cam from Patrick's. Totally different exhaust note. It sounds like it wants out.

regards,
Leon