Ok y'all,
I have a 2000 with a 5 speed, headers and a bbk cold air and now I would like duals. The question is, are true duals realy any better than after the Y?
It's debatable with a mildly modified six like yours. If you had P+P heads or forced induction, I'd say definitely go with the duals, but I don't know if a mostly stock 3.8 would be able to use the extra flow.
I have a cat-back dual setup, mostly for the appearance and sound. If I ever add a blower, I'll definitely go with duals, but for now I think the Y-pipe is needed for back-pressure.
Since you already have headers and a CAI, duals certainly won't hurt and will complement those mods. If you do go with them stay with 2 1/4" pipe diameter (as in the stock setup) to maintain backpressure as Skymarshall posted. A GT takeoff catback and fabricated midpipe provides a good, inexpensive means of doing so