do a search on this forum about the Street Bob, Jeckyl and Hyde mod for the stock mufflers. spent about $40 and got great sound. sounds nice and deep when cruisin, but holy $h!+ when you get in the throttle.

 

Or...I drilled about seven 5/16" holes around the periphery of the stock muffler plug...you'll need a long drill bit. Then I drilled 3 more near the end of the pipe up into the baffle (on the underside of the top lip to be invisible). Really like the sound (and prefer the look and quality of the stock tapered cans). Installed a set of O2 IED's and the bike couldn't run better. $70 total investment (for the IED's...probably not necessary).

Just a thought.