So I have a slightly leaky original exhaust manifold on my original 302 with a mild cam and was planning on getting the 289 HIPO manifold since I mostly cruise and dont think the added power of headers will do much for me considering the RPM range I am normally with my c4 (plus the cost).
Currently I has a single exhaust going into a turbo muffler from midas/mieneke. I like that my car is fairly quiet but still makes a nice low meaty sound when I touch the accelerator.

Will the new hipo manifold and changing to duel turbo mufflers w/ an H pipe and 2.25in piping make my car quieter or louder? My brain says two mufflers each having to deal with less exhaust than one would make it quieter.

http://www.cjponyparts.com/mustang-e...5-1973/p/EXM4/