For a '97 Id do the entire catback. I only had Flows welded in on mine, but it was only like 2 months old when I did it lol. Plus Im not sure, but arent the '97 pipes a smaller diameter than 99+?
i have mufflers on mine although our cars are much diff i dont see the point in buying a catback to make min. power giver or take 2-3 hp woohoo ... ya right unless u have a power adder u wont see that big of numbers off of this where u make power in the exhaust is long tubes and xpipes
actually in the end the 2.25'' piping is going to hurt you...especially if you go supercharger or get headwork done. the extra .25'' helps but your right stock otherwise it isn't going to make even 3 hp difference. but when it becomes the bottleneck of your exhaust its gonna to be alot more than 3hp your losing.
I have the mufflers welded in my 97 Cobra, and I was told by a fellow SVT owner that switching to the catback will make a critical difference in HP and even sound on our 4V Cobras. He said I should expect to pick up 5-7rwhp by switching from the flowmasters welded in and the flowmaster catback, and also gain a louder, deeper sound. I am all out of money though, and I don't want to downgrade my 3" x 22" welded in tips to the 2.5" tips that come with the catback.