Nick996

I'm trying to use OE parts on my 2011 GS to get some inexpensive gains. The price of aftermarket parts are just insane for the gains they give.

$900 for a Fast intake manifold isn't a bargin IMO.

If the LS7 TB/Intake manifold doesn't fit, what are the gains for porting the LS3 OE TB/Intake manifold?

0peakspeedshop

No, you can not directly swap out your LS3 Intake Manifold for the LS7. The port dimensions are different between them. Here are a few pictures that shows the two side by side.



LS7 (left) and LS3 (right). The overall length and width are the same but the LS7 has a flatter profile.



Here you can see the port dimensions are different. (LS7 on left)



Here is a close up of the ports side by side. (LS7 on left)



This illustration from CompCams is very helpful.

The LS7 and LS3 throttle bodies are the same model for your year.

Having your current LS3 throttle body and intake manifold ported is very worthwhile. Basic porting of your intake manifold will gain 7-11 rwhp and Radical porting will gain 12-16 rwhp. For the difference between the two you can go to our web site at http://www.peakspeedshop.com/

Porting your throttle body generally gains a few more horsepower, but you will benefit most by the crisper throttle response.

0peakspeedshop

By the way, Peak Speed Shop is offering a deal on porting right now. We are a Supporting Vendor of the Corvette Forum. You can check out our special at the following thread:
http://forums.corvetteforum.com/c6-t...y-porting.html