Anybody running the Chevrolet Performance CNC ported LS9 heads? The part number is 19328743. Was thinking of using them with BTR Ti retainers and PSI 1511ML springs. One of the things I like is the nice bump in compression right out of the box without having to mill them due to smaller combustion chamber. Undecided on what cam to run yet. These would be for a manual LS3 2012 GS. If you're running them on an LS3 what was/is your experience with them?

 

What is the chamber volume stock? I'm looking to switch from the GMPP CNC LS3 heads to a CNC LSA or LS9 head due to it being a much stronger material. I'm worried about lifting an LS3 head with bigger boost. I'm very hesitant on the LS9 head though but they have the same guide issue as the LS7 heads.

Then when it's all said and done how much more would the new AFR LS3 head be? That is heads and tails better than any GM casting and is roughly $2,600 depending on what options you want.

Best case scenario is finding a used set of already CNC'd LSA heads, but they're few and far between!

 

LS9 chamber volume is 66.5cc so about 2cc smaller than the LS3 heads, which come in at 68.5cc.

I hear you about the guides because of the Ti valves, but on the Corvette Forum I am not seeing the same issues with the LS9 heads that you see with the LS7 heads.

And I hear you about the AFR LS3 heads. I am also considering those, but can't get a bump in compression with those without milling them.