I love my gutted stock pipes, they sound great, didn't cost me anything except some time, and my dyno number were great. It's not a hard job, I have done quite a few sets now. I did all mine with an air hammer and curved exhaust chisel with an extension I made, but a piece of rebar sharpened to a chisel end works too. Be careful to leave the reducer cone in the header end of the pipes or you will lose bottom end torque. Some guys have had a problem with catching the mesh that lines the inner wall of the pipe for the whole length after the first baffle. You can use a metal cutting hole saw for the first baffle. put the large blade on the center first then one about the size of the small pipe in the center. Both blades in at the same time the smaller one acts like a center drill. Be sure to use cutting oil to keep it cool so as not to discolor the chrome. The rest of the baffles knock out much easier since they are just spot welded to the mesh. If you want to do the air hammer method click the link in my sig and you will see shots of the tool I made to extend my air chisel and also the chisel I use.
