Ed, you are correct. This will be a very big project. Another consideration is that the teams have perfected the construction of a racing chassis. They will only use metal from the same production lots and they have exacting construction specs and techniques, so that one chassis build is nearly identical to another. If the chassis supplier cannot meet these standards, there will be a revolt among the teams.
In the early 2010's the manufacturers had a "come to Jesus" meeting with Brian France and they laid down the law. The manufacturers will only participate in NASCAR if they run the cars they want with their engines. They will work with NASCAR to make sure the competition is fair. But the days of France, Sr. and France Jr, pitting the manufacturers against each other, so the France's could do what they pleased were over.