NeedAJoker -- believe Sal's point here is that SSIs do not provide any real upgrade over the stock 3.2 exhaust setup with a cat delete. Brian/M&K's active premuffler takes things a step beyond a cat delete as it (at least partially) bypasses the back pressure created downstream of the cat/premuffler by the muffler itself. And, the beautiful noise it creates at full throttle sure doesn't hurt on the "butt dyno" front. Here's a direct link to the M&k active premuffler
https://mkexhaust.com/active-exhaust-with-pre-muffler/