do you want to get more power out of your fmf pipes. if so take your power core 2 silencers of and disasemble them like as if you were changing the packing. now take the muffler body and cut 2-3 inchs of of it. do the same with the inner of the silencers and then repack them and put back on. its just like the shortys. it give a good power gain. my buddy has did this and he says it make a good amount of low end and mid rang increase. so try it, it doesnt cost a thing.