I have a 1998 Mustang GT and i was wondering will 1999-2004 Mustang Gt cat back system work on my car with stock h pipe and what is the difference in the two system also what would I have to do to make the 1999-2004 system to work on my Mustang the brand of the two systems that I am looking at are SSS exhaust and SRS I would love to use one or the other thanks for the info