I am not really a mechanic, but I don't think there would be a problem with it.
But if you are looking for a more mellow sound, not so loud, I would recommend Dynomax Super Turbo Mufflers, p/n: 17731. They increased my HP approximately 6 to 10, for the pair. I just had a 3" Downpipe and High-Flow Cat Assembly installed last Friday. It increased my HP another 11 HP. It sounds mellow, not raspy sounding.
Dave SSEi, 2001 (black).
Make sure the "Y" is level with the rest of the pipe, before and after it. If you can't have the entire pipe level then I wouldn't do it. I am just a technical systems support person, a former CTM in the Navy. Any mechanics have any suggestions.