The Magnaflow Y-pipe you need is #10778. The Y-pipe, muffler, and manifolds are all restrictive, so there is alot of room for improvement there. The full catback kits are very nice, but you arent going to see much of a performance gain going that route over just having the Y and muffler replaced. The main reason why I like the full catback kits is that you can install them yourself in an hour or so, they bolt on very easily using the factory hangers, and it is very easy to remove when it comes time to sell the truck. I dont trust any of the exhaust shops in my area, so I would much rather buy a bolt-on catback then pay a shop to do bad work on my $50k truck.
