I've got a pretty heavily modded 383, see sig for info. I currently have long tubes, off-road Y-pipe, and a Magnaflow 'cat'back on it. Going to need some type of cat for inspection. I could just get a fake hollow cat, or get a clamshell welded on. On the other hand, maybe having high flow cats will make my eyes burn a little less?

I don't need them to pass a sniffer, just a visual.

My AIR and EGR systems are deleted, if that matters.

If I understand cats correctly, I need to put a pair up as close to the header as possible, preferably mated to the flange? Sticking a single cat after the Y-pipe won't really do much eh?

Talked to the local exhaust shop that did my tips, they seem to do good work.

$175 installed for either of these. I don't know if it would be x2 for two, or just whatever the hourly labor rate is, but, roughly $350 for a pair.
100 cell:
http://www.mandrelbendingsolutions.c...sh-Flow/Detail

300 cell:
http://www.mandrelbendingsolutions.c...er-High/Detail

The 100 comes with no documentation, the 300 comes with whatever stickers and documentation. I don't know if it matters.

Just looking for some guidance here. Thanks.