Need help with X-Pipe

I bought an '01 cobra that has cat-back flowmaster 40's. My issue is the guy hacked everything from there forward (universal cats welded in to 2.5" pipe. It has stock exhaust manifolds. If I buy a Magnaflow Cat'd X-Pipe, will it bolt right on? I don't care to go the header route. Presently is true dual exhaust (no H, no X, no connection between the two). Will I see any performance / sound increase with the X-Pipe?