Conversions & Hybrids - Exhaust setup

I've almost finished my swap and will be taking it to get the exhaust done soon.


The headers that I am using have a 3" collector, and my car is best suited for a single pipe out the back. So here are the options that I'm considering.

1) Headers -> Two 3" cats -> Y ->3.5" pipe w/ single Muffler

2) Headers -> Two 3" cats -> Y ->3" pipe w/ single Muffler

3) Headers -> Y -> 3.5" cat -> 3.5" pipe w/ single muffler

4) Headers -> Y -> 3" cat -> 3" pipe w/ single muffler

Any thoughts on which route would be the best? My engine is a Camaro LS1, with a TR227 cam and stock heads.

You should check to see what way performance exhaust for the f-bodys run. I THINK they run the cats on the end of the manifolds then Y into a singe pipe back to the muffler where it is split back into 2. So a performance exhaust system for an F-body *should* be a good reference for the size pipes that will work with the engine package.