Mate, if they're anything like the 2010's that were sent out here to OZ then you gotta loose the headers.
Take a look behind the upper pipe and see what looks like a damn exhaust brake thats controlled by a magic box via cable. It shuts off that pipe and forces the exhaust out of one pipe only until the engine reaches somewhere around 2500 RPM.
FWIW, my choice for the 96 CI was a set of V&H Big Shot Staggered complimented with a stage one air kit and SERT.
Sounds like an H-D should,,, Awesome.
Link to some pics