The LSA is the SC'd 6.2 in the CTS-V that makes 556 HP.
The LS7, last I read, is on it's way out of production.
It seems to me the LSA is the best bet. It's likely cheaper to build because it doesn't share as many of the exotic metals the LS7 and LS9 do. Also, it's not build at Wixom, but in Mexico, if memory serves. I think the dry-sump oiling system is another drawback to the 7 and 9.
Unless a Gen V makes it before Z28 returns, I think it'll be the LSA.
Search the thread Tran suggests though. There's no concrete proof of anything, though, either way.
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