If you have stock v6 exhaust any gt cat back will bolt right up IF you buy a dual exhaust adaptor OR have the Y pipe (where the pipes merge from each header into a single pipe) cut off and have the GT cat back put on with some adaptor pipes to line it all up, both are done every day just depends on which you want to do (using the adaptor works better cuz you can just bolt up the cat back, dont have to hack it up, and you can unbolt it to get to the tranny and what not.
Steeda, pace setter, etc have v6 dual exhaust adaptors.
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List
- Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)