I posted this last month in the gen IV external section but figured I would put it up over here. I'm gonna try to get back to the dealer to see if there is any work on a release date.
From page 223 of the 2009 GMPP catalog
E. 19166952 NEW
LSX-LS3 Dual-Plane Standard Deck
4-bbl Manifold
• Dual plane for low and mid-range torque
• L92 style ports
• Injector/nitrous bosses cast-in
• Extra thick for professional porting
• 4150 style carb. mounting provision
• Uses OEM O-ring gaskets (included)
• T all-deck version available as P/N 19166953

 

That would be cool to have a dual plane. The L92 heads are an over achiever up stairs. A little velocity couldnt hurt.

 

This is something I have been wondering about for some time. Doesn't it seem kind of self defeating to put a dual plane on L92 heads? Not criticizing, just asking. Sort of like buying a set of 225 AFR’s for a first gen then using a 2 barrel intake.

If you want low RPM velocity, why not stick with cathedral port heads?

 

If its a RPMperformer intake I'd go that rout. There was a big difference (bottom,early mid) between single vs. dual plane on a LS1 cath. port heads. It would make the car more fun to drive on the streets. My .02

 

x2...that is what I was thinking.

 

Big block Chevy heads seem to do VERY well with an EDelbrock RPM intake. I would think L92's would do the same. How many times do you see above 6500 RPM when you're out driving around? LOL. If you do, you live in a much different neighborhood than I do. I would buy one, if it compares to an Edelbrock RPM and NOT the regular Performer. Ron

 

In the sbc world a performer rpm airgap makes overall more power and more average horsepower than the victor jr. With a dual plane the torque and hp will usually come on earlier. I single plane will usually make more peak horsepower.