I have the Packs on my 94GT with stock cats...I love the sound! It could be louder & pop more on decel for my tastes but it really is great! No drone, nice & deep, it turns heads when on the throttle even slightly & pretty good at WOT, a lot louder then. Sounds perfect cruising on the freeway.
BUT, still quiet enough to not interest my local cops if I keep the revs down. My wife can hear me coming blocks away and when you fire it up people notice so for now I will leave it alone.
on edit: JFYI... the 5.0 Magnapack catback for a 94/95GT is the same one for the 96-98 4.6L engine!! I would have never guessed they are the same...I had to reposition one hanger rod on the passenger side for some reason. Just bolted right up.