The axel back is the same on both M6 and A6...the difference is in the middle...their is a huge resonator on the A6 (to supress the sound of the AFM kicking in).
With TM gone from the Tranny and the headers on, it has certainly become a quicker ride. And now it sounds appropriate for what it is.
2002 Camaro SS. 408 LS2. 500+RWHP/480RWTQ. Full UMI RR suspension. Koni/Strano. 295F/315R. 3500#(55/45)