I have the DG stage 3 exhaust, and the power gains with the pipe are better than stock, but they aren't going to be anything really substantial. Just a little more torque, as if the 350 needed more, and you can pull longer in the mid range, and top end is slightly better than normal. I like it, but I paid too much for it. If you can get it for dirt cheap then go ahead. It's better than stock. Don't know much about the Jardine.