I had the same experience with mine. The clamps that came with the A/T mufflers wouldn't clamp down tight enough. I went to the local hardware store and spent maybe $5 for a pair of really good ones and it fixed the problem.
Off Road H or Prochamber. No X.
I'm planning on going the prochamber route with my flowmasters.... everything I've heard says don't go X pipe if you want sound from the combination. I haven't heard it but the general consensus is axle back + X pipe = But axle back + H pipe =
I know the pro 5.0 use to be real popular with the fox body crowd, it just seems we perfer the MGW or hurst for the S-197. As for myself, I've just allways used hurst from back in the 70's when I first started driving and playing with ford muscle cars. Beings my 07 is so retro looking, it has to have a hurst with the hurst emblem on the truck lid. As far as modding, it's sorta like a diease, once you start, you can't stop.