Just installed Pacesetter Headers w/ORY
-If you want throaty, keep your ORY pipe. Putting cats on will only make it more mellow and quieter.
-Don't put the Loudmouth on. That will only get you the "that guy needs a muffler" sound.
-If you want a rumble, a cam will do that for you. If you're looking for a catback to do it, I'd say go with either GMMG or maybe Magnaflow. I know my Magnaflow with LTs and ORY had a nice, deep gurgle and rumble to it. GMMG just always has that sound though.
Good luck.
Complete die-hards of iron blocks/old school muscle/big block-type sounds may never be happy with an LS1.
The rest of us just find ways and combinations of exhaust and cam work to make the LS1 create sounds worth drooling over.
Please keep in mind that this is my honest opinion and others may differ


You could try a loudmouth cat-back. 