I have my cutout right after the cat, it virbates a little ( ) but it's seems better there than further back.

 

I have my cutout right after my collector of my y-pipe...Yes, it makes certain parts of the car rattle, but who care?? Sounds like a pro stock car at WOT...

 

I highly sugguest against it.

Ground clearance sucks soooooo bad with it, and gets even worse with power plates. I had maybe 3-4" of ground clearance between the driver cutout because there is simply no room down there. It was only 2-3" with the cutout plate. You know those dips between the street and someone's driveway or business, rain gutters? You'll bang them every time, sometimes over big speed bumps too.

I did not see any gain with the dual cutouts over the 3" true duals, x-pipe, and dynomax's. The dual cutouts are so loud, even with the LT4 KM, it dials in false timing retard. I didn't experience that problem with the true duals. At the same track, on very simmilar days (temp, baro press, humidity) both exhausts ran the same times.

Edit: Plus, taking those plates off is a pain if you don't have the power plates. It took me about 10 minutes just to take them off. I get out, get on the ground and start taking off those 3 bolts with a ratchet. Wing nuts didn't work for me, I couldn't get enough torque on them and they kept coming loose. So I put on regular nuts.

 

This weekend I'm gonna replace my cat with a cutout. My mechanic is gonna fabricate a flange and weld it to the cutout. This way it can pretty much be a bolt-on piece. Now I have the option of switching back and forth whenever I want. My car doesnt' need to be inspected for another year so this works out nice. I tend to agree with Kain about the ground clearance issue too. That's why I'm choosing this setup.