Slp Lm2
It will be louder and you'll pick up some HP, should be a simple bolt-on after removing the flowmaster and stock mid-pipe (I-pipe). You may need to cut the old over-the-axle section out though.
Power gains will be nothing to write home about from stock to LM2, but might be felt from Flowmaster to LM2 considering the Flowmaster is more restrictive than stock. I personally love the sound of a Flowmaster 80, and would keep it along with adding a 3" electric cutout if you want to be loud and make a little more power.

but supprisingly after LT's and ORY the highway driving noice didnt really increase (but in town sure did)
ohh and BLK02TA shouldnt u be under 2k at 80mph since ur M6..


