Anyone have any experience or knowledge of the GM factory's accessory cat-back exhaust system they offer on the 2007.5 and 2008 trucks? Price, noise level, performance gains, etc? They show at least two versions, i.e. "performance" and "touring". Not sure if the option was available on pre-2007.5's.

Where did you see these mods? And, how much were they?

Where did you see these mods? And, how much were they?

I saw them in the 2007 GMC 2500/3500HD brochure in the "accessories" section in the back and when you go to GMC's 2500HD Sierra site on-line and click on "accessories" on the left side of the page they are shown. I haven't asked the dealer what the cost is, yet. They are a dealer installed option. If the price isn't bad I'll have them throw the exhaust in the back when I take delivery of my 2008 GMC 2500HD and I'll install it myself and save the labor, if they'll do it that way. I seriously doubt there is a core credit given for the "old" exhaust.

I added this option on my truck when I bought it, they actually had a local shop do my exhaust system. I could have had the Chevy system installed, but he said it interferes with the spare tire, so you would have to remove it.

I added this option on my truck when I bought it, they actually had a local shop do my exhaust system. I could have had the Chevy system installed, but he said it interferes with the spare tire, so you would have to remove it.

You "added this option" on your truck but you ended up installing a Flowmaster cat-back exhaust instead? Strange Chevy would sell something that, in essence, doesn't fit. I guess they figure you can carry the spare in the bed ;) . Do you remember what the price was on the factory system? I just ordered a 2008 GMC 2500HD, ext. cab, long bed, 6.0L with 4.10's. If the factory system wouldn't fit yours it probably won't fit mine, either, seeing that they are both NBS's with the same frame length (I think).