According to an NPR story, Ventech, a maker of ventilators (note its name), needed help with its part supply chain to make so many more at a time, and that it partnered with GM because GM could help it with that.
Interesting, because e3verything else I'd heard was that GM was asked to make ventilators and it sounded like they found Ventcch.
continuing, GM found (knew?) a place in Minnesota that could make one pparticular part, a piston, in large quantities.
I heard the story on Morning Edition, where sometimes each story is separate and you can hear one at a time.