Wow!
I wonder if the block is a "clean sheet" design, or if it's based on the LS/LT, as the 3.4 DOHC was based on the V6-60.
It does retain the same bore centers.
Edit - Nevermind. That block looks nothing like an LS/LT block. I'm surprised that GM actually coughed up enough coin to make this happen.
Hmmmm... I wonder if it has anything in common with the Caddy Blackwing V8.
2nd edit - Nothing in common with the Caddy. GM must have some money stashed away, someplace.
Side note, from Car & Driver article.
"Every Blackwing is assembled in the same Bowling Green, Kentucky, plant where the mid-engined 2020 Corvette will be birthed, and we expect the spiciest versions of that car to be powered by overhead-cam engines. But rumors suggest the most powerful Corvette engines will not be based on the Blackwing and will instead use a flat-plane-crank V-8 with turbos mounted on either side of the block. ..." Turbos? Apparently not.