Last week, GM Authority reported that the base model of the upcoming mid-engine Corvette C8, set to be called Stingray, will be powered by the 6.2-liter LT2 engine that will make around 500 horsepower. And now, less than a week before its unveiling, GM Authority has obtained new information about an upcoming GM twin-turbo engine, dubbed LT7, that is earmarked for a future high-performance variant of the Corvette C8, potentially the C8 Corvette Z06.

You may have seen these CAD images of the LT7 engine before, but there’s now some info to go along with the photos. So, GM will switch from blowers (superchargers) to snails (turbochargers) in its range-topping Corvette models. But don’t let the LT7 moniker mislead you: the engine portrayed in these GM CAD images is not based on GM’s fifth-generation Small Block / push-rod LT engine family, which includes the familiar LT1 (for the C7 Stingray), LT4 (for the C7 Z06), and LT5 (for the C7 ZR1). Instead, the LT7 is based on GM’s new Dual Overhead Cam (DOHC) V8 engine architecture initially introduced by the 4.2L Twin-Turbo V8 LTA, otherwise known as Blackwing.

Don’t expect to see or even hear about this new Twin Turbo LT7 V8 engine during the Corvette C8 reveal next week, since that event will be dedicated to the base model mid-engine Corvette, aka the C8 Corvette Stingray. Instead, this here LT7 will go into what we expect to be the C8 Corvette Z06, which is at least another 16 months out, if not more.

Current information about the LT7 is sparse, but we have uncovered that it will have a larger displacement than the 4.2-liter Blackwing LTA. Sources tell us that the LT7 will make more than the 650 horsepower generated by the supercharged 6.2L LT4 V8 in the C7 Z06, and well more than the high-output version of the Blackwing LTA, which is rated at 550 horses and 627 pound-feet of torque. It’s currently unclear whether the LT7 will share the same block as the LTA, or if the two engines will only share the same overall engine design/configuration, and not size.

The CAD images also show that the turbochargers are not mounted in the ‘Hot V’ design of the Blackwing. Instead, they are placed on either side of the Vee, below the cylinder banks. As such, the twin throttle bodies, intake manifold, and entire induction system differ from those of the Blackwing. We’d imagine that the head design varies as well.

Another point of interest is the cooling setup. Since this powertrain is for a mid-engine car, it doesn’t have a conventional front-mounted intercooler. On top of that, the DOHC Blackwing architecture utilizes water-to-air charge cooling, making the overall packaging of the cooling system very different from anything else GM has shipped in the past. Then again, a mid-engine sports car is already entirely different than anything in GM’s current portfolio.