Hey all,

So, just a quick question for you guys running TBI setups w/vortec heads, who also have to pass smog. For the longest time, I was under the impression that the GMPP TBI Vortec Manifold (This one - http://www.summitracing.com/parts/nal-12496821/overview/) was the only smog legal/EGR provisioned intake available for TBI.

However, it turns out that GM also makes a carbureted vortec intake with EGR provisions as well - ( http://www.summitracing.com/parts/nal-12496820/overview/)

Just curious if anyone here has experience with the carbed one? I'm leaning towards using one with a TBI adapter plate, mainly because I want 2'' bore inlets for the TBI, and it's my understanding that you'd only have to bore out the adapter plate holes to 2'', versus having to have the manifold itself bored out w/the TBI-specific one (Correct me if I'm wrong, though!). Any other factors I should consider before going the carb-to-adapter plate route vs a TBI specific manifold?

Thanks!

 

I am running the GM cab manifold with the 454 tbi and 454 TBI to Quadrajet Adaptor Spacer – 1.75 inch - P/N 10045799. Originally thought I needed the EGR to pass smog test but it turns out with the cam I am running I do not need the EGR. This setup with a 3" open element air cleaner will not clear the stock camaro hood. That manifold with an adaptor plate should clear the 2" bore if the tbi is placed towards the rear. Many square bore manifold still require some mods to clear at the edges.

 

Where does that 2nd intake get the exhaust gases from?
Oh, I see it gets it in the same place as the vortec v8s do, you need a tube from the exhaust manifold.