So I searched high and low in the interwebs to find as many comparisons as I could to see how much power can be gained from gutted cats. I recently added gutted cats and a ported LS7 throttle body to my car but I'm posting in this section because I think the cats contributed more to my power gains than the TB did. From gutted cats and a ported LS7 TB my car picked up about 29whp and 43wtq! I know these numbers can fluctuate depending on many different factors but this was the best comparison I could get and it's good enough for me. Either way, my buddy gave me his cats for free so it just took a little elbow grease and 80 bucks to get them gutted and installed. I also picked up a ported TB for 180 from a guy on this forum. I can't complain for 260 dollars in mods! If you haven't done headers or are looking for a deeper tone and a decent power mod I'd recommend going this route! That or B&B test pipes....Either way she feels and sounds like an absolute animal!