I have the eccentric habit of buying stock pipes when they go for very cheap, and modifying them to different tunings & tasks. (Why be normal?
) Quiet for long trips, loud for performance, and another set dialed in for MPGs.
Anyway - It's my belief that the later stock mufflers have much heavier spot welds on the baffles than the earlier ones did. I too had a helluva time trying to bash the baffles out of some late model stock pipes, whereas my 05 pipes gave up the welds very easily.
A few holes drilled into a baffle via a 3/4" hole saw fixed to a length or two of 1/4" drive socket wrench extension* can readily weaken a baffle to the point of collapsing it, then one can often do the bash procedure & pull the deformed baffle out with a length of coat hanger. Some tape on the extension joints takes enough wobble out of this contraption to make it user friendly. A Sears tool store has everything you need, or I can loan you the extension set up. My 3/4" hole saw is now toofless, so that would be up to you.
Not to bail on you, but if all else fails, consider a set of after market Bubs. They can be had for around $350, and may (or may not?) increase HP. I've yet to buy any after market pipes, for the babies seem to always need a new pair of shoes.
*There is a little drive piece that makes this work - It's about an inch long, and one square end of it fits into the 1/4" socket extension hole, and the other end is a hex shape that fits into the drill chuck. I don't know what it's called though.
