ok, here is the lowdown on the flowmasters. The axlebacks that you see on their website were specifically designed for the 3v heads. THe older super, delta, and regular 40 series were not. That is why the mustangs with them sound more like a BMW or a Benz with a v8 instead of a MUSTANG. I didn't like it so I changed them out. I had the 40 series old school flows on. Drone was bad bad in the car and it really wasn't that loud outside the car. There are other companies out there that are producing exhaust systems specifically for the new motors. But you are never going to get the sound that the older mustangs had because the new ones don't have a tailpipe at all. your tip is welded directly to the muffler. I just went with Pypes off-road x and violator axle-back set up. Very loud but VERY raspy also. May swap out the x for an h pipe. hope all this helps ya.

HUTCH