A body 383 or any other factory installed dual exhaust applications were not equipped with an h-pipe. 1968 383 GTS and Barracuda 383 dual exhaust were piped the same as the 1967 models which were quite restrictive. The flange pipes were 2.25” midway back where 2” tubing was welded in to complete the routing into the 2” inlet mufflers. The tailpipes were also 2”. The exhaust tips in 1968 were 1-7/8” O.D. and only 1-5/8” I.D. for the exhaust to exit. It wasn’t until 1969 that pipe size was increased on the 383 equipped a body cars even though the exhaust tips remained the 1-7/8” restrictive size. This was true even with the 1969 M code 440 cars which used the 383 exhaust system other than the left 017 casting exhaust manifold and the right flange spacer plate.
