While the C7 chassis is yesterday's news for the Corvette, it's still a very advanced, refined and capable chassis. Reusing that chassis would be an economical way to bring a "new" Cadillac halo car to market. Basically use the twin turbo engine from the C8 ZR1, detuned to 800hp.
Won't fit in front engined Corvette chassis. It's one of the many reasons why a DOHC was never considered for the Corvette. Don't say, "but.. but.. what about the Norrrrrthhhhstarrr!?" Junk engine, and a teeny one at that. Only way to get a DOHC under the hood of the C6's chassis was to use a small displacement, very anemic version.
GM did the C7 ZR1 for a single year - 2019.
I'm well aware. It was actually an extended year and a half or so. Almost a 2MY run. The 2019 Corvette was an odd duck for the overall length of the MY.
The thing you're failing to mention here is that: the Corvette bought and paid for the ZR1. There was no ZR1 in the original C7 plan. The Z06 was going to be the top banana. But they had to stretch the 7th gen out a bit longer because the 8th gen wasn't ready as soon as they'd planned, so they did some body mods, hood mods to drop the bigger supercharger in, tweaked the suspension, and spent some time on the aero. But all of that stuff was
relatively (please note the emphasis) easy for Mero, Bennion, and the others to handle. Why? The C7 already had a long enough run with plenty of development.
Being a complilation of existing off the shelf parts other than the body there would not be great design, engineering and tooling costs to bring it into existence.
You're failing to understand how much work this would entail for GM to simply bring the 7th gen chassis back though. Who's going to build it? Which factory? It can't be built in BG; they're trying to keep up with C8 chassis builds while helping GM with the build of the C9. So it would have to be another plant. And you're assuming all of the bits and pieces they used to make the C7 chassis are mothballed somewhere in a GM warehouse, ready to be deployed to another factory.
So let's say they do that. Cool. That just cost 10s of millions of dollars just to get going again, probably more. Hundreds if they have to build an entire new factory for this.
Before GM goes and puts this 2010 or so designed chassis into production again, they're going to need to do a development pass on crash worthiness. Bearing in mind that impact safety gets harder and harder to meet each year, and the C7's chassis hasn't had to meet any sort of regs since 2019. Things have changed in the last 7 years, so someone has to work on that.
That, by the way, will change the interior layout of the car because of thicker door panels (side impact), possibly overhead impingement on the cabin if any new roll-over regs are in place, maybe the dash attachments have to change to deal with frontal impacts, etc. It's not as simple as you may believe. Theres a TON of work that'll go into it, and that work costs major time and $$.
OK. GM has the chassis build set up in a new or existing plant, and they've worked on the crash worthiness of it. Some changes had to be made, interior layout may be a bit different, but they can work with it. Now we come to the body design. Who's going to do that? Which aerodynamicist specialist are they could to task with this? Bennion's gone. He's retired. And he's the primary guy responsible for the C7, so he can't help. Body design with fluid dynamics can take years, even with fast computers and very good artists and developers. Millions and millions will be spent here, too.
Suppliers for all the parts and pieces will need to increase their output again, as if the C7 were back in production. They're all still making spare parts for the C7s, but they'll need to kick those lines into gear to make more. Renegotiating those contracts will take many more millions. Those suppliers will all have GM by the balls with that, and they'll have to pay.
Finally we get to the power train. "Just slap a de-tuned LT7 in it!" They can't, as I explained above. And the Gemini engine is not destined to be used in any other cars besides the Z06 and ZR1. BG simply can't make enough of them. That block is dead
as far as other GM products go (read that carefully). So it's going to have to be something else. But what?
That brings us right back to the topic of this thread: a charged LS6. And for all of the reasons I already listed, it just doesn't make financial sense for GM to even consider doing that. Even if the Camaro lives again (still not confirmed, just rumored), the volume of ZL1s is a pitance compared to what GM produced with all of the LT4s during the C7 run.
Your idea is a dream, nothing but a dream, and could never, ever happen. GM would lose their absolute asses on this idea. There's absolutely no upside for them, at all. Financially it's way, WAY into the red, and the press would jump on this in a heartbeat (see what I did there?) wondering, "WTF are they bringing that old chassis back!?"
Nope.