2000 Sierra ext cab 4.8l Exhaust

OK guys, i know i'm not a silverado, but this forum gets more action.

I am looking to upgrade to a cat back system. Ultimately i want the deepest sound w/o killing my ears on the highway. So i've been looking at the flowmaster 50 series mufflers. I was wondering if they made a higher series than this for my application. i am looking at getting a single in dual out flowmaster, but after that what diameter pipe do i need to get the sound i want w/o the flow restriction?

what is the diameter pipe coming off the factory cat that the muffler will attach to? I was thinking about just getting the muffler and having a shop make the pipes. also has anyone seen the single cat pipe split and then had 2 mufflers put on it for the dual exhaust? or is this just counter-productive?

basically i'm trying to figure out the setup to get.

any help would be apprciated on explaining the taper down or up pipe diameter thery, and if i'm just keeping the single cat, what my options are.

thanks so much guys, i am more of an engine interals man. educate me please.

I had Flowmaster on my 94 Silverado and my new 04 just got it last weekend. Whether you get a 40,50, or 70 series your air flow will be the same, so will the muffler air capacity. I had similar questions so I called Flowmaster and got the info. The only change is in sound. The 40 series on my 04 is a bit to loud for my taste inside the cab so I will be switching to the Delta 40. All this adds is three "V" shaped baffles in the muffler. Pipe diamter is going to be specific for each application. A good muffler shop will know this. It is important to maintain back pressure. This is when the pipes are to big and air can actually free flow back into the system. It would be like one long lasting backfire. The pipes on a V8 are 2.5 - 2.75. In the 4.8L they are just slightly smaller. Go to the flowmaster site they will show each application and what pipe diameter is best. The single cat pipe split would help with a high tune engine. This is where people install an " H " pipe and use two mufflers. In your application, waste of time and money. Just my .02
If money is not a factor chek out CORSA. www.corsaperf.com If I wasn't on a budget this would be on every vehicle I own. It was on the 02 Avalanche I traded for my Silverado.

Good Luck.

i have single in and dual out flowmaster series 40 on my 5.3 and at about 80mph it is a little loud but not bad at all. i would think it would be quieter with a 4.8.

yeah, that and i'm gonna get a 50 series if possible. Are ther 70 series that are available for my application. I mean with the proper in put and dual out put diameters. What should input and dual output diameter be? 2.5 in and 2" out?

even though i like flowmaster i would go with a gibson split rear stainless exuast since gm comes with stainless exaust. it will provide a deep tone more hp and tourqe and last forever. Thats what im planning on putting on my 2000 5.3 siverado.