Ported L76 Intake results as installed on the following combination:

Car Owner: Ivan 
Car: 2006 GTO

Mods:

Stock shortblock LS2 6.0
Flycut stock pistons (0.20)
Comp Cam's Camshaft: 234/238 @ .050 , 595/605 lift, 114+4
ETP Prepped L92 cylinder heads (cut decks to make 11:1 compression, blended bowls, back cut valves, 
5 angle valve job,  shimmed springs)
Kooks 1 3/4 full length headers
Corsa Sport Catback
Underdrive Pulley
LS2 Port Works Ported L76 Intake
LS2 Port Works Ported Stage 1 Throttle Body 
Cold Air intake
160 T-stat

Installed and Custom Tuning by Ed Hutchings at
Automotive Technology, Inc. - Chesapeake, VA. 757-424-1740 

You can find Ed's web page here- www.thehpfactory.com


Dyno run 20 is with all mods and a stock L76 Intake Manifold.
Dyno run 22 added the ported L76 Intake Manifold only.


Tested alone, the intake porting gained  12 RWHP Peak and 16.68 RWTQ Peak.  
Gains under the curve were

The Final Numbers were 486.95 RWHP and 435.58 RWTQ.  


Don't overlook the gains UNDER the CURVE -  UP TO 20 RWTQ was gained!