please help need perfomance answers on what to get
An elec. cutout in the I-pipe (the pipe that goes from the Y-pipe to the over-the axle pipe) will make things loud enough, and free up a few ponies. If you haven't gotten an induction lid by now, do so, it's worth about 10hp and it's the easiest thing to install.
If the exhaust is designed well it should have little or no effect on the flow rate, so a cut will not help here. The only thing it will do is effect the exhaust pressure wave, but it's easy to effect it in the wrong direction.
Try the links in my sig for help, and have a look through the sticky's in this forum and the New to LS1's forum.
It would also free up a few ponies over the stock catback (and yes, while changing the available tq to a much higher point in the rev range).




