When I was on the factory tour as part of RedHot's Museum delivery, every C7 coming off the line went through a dyno set up including where they ran the engine up to 70 mph and completed somewhere in the vicinity of 600 electronic related tests.Yep, there are as many options on new motor run is a their are members on this site so take whatever you read here with a grain of salt. If you don't have first hand knowledge of what is involved in a new motor run it then simply follow GM's guidelines and you're good to go.
There's also a school of thought that says the motor needs to perform certain stress actions BEFORE things like the rings take a seat. Many manufacturers already perform this action on the checkout dyno within minutes of the car rolling off the assembly line. I have no idea if GM does. The action is hard acceleration through the RPM range to about 80% of redline followed immediately by full engine braking. This applies maximum load to the rings from both directions allowing them to seat properly to prevent compression loss and oil leakage over time. This actions should be performed at least 2 times before the motor has more than 1 hour on it to be most effective. With modern metallurgy most parts have no wear in pattern, it's only the rings that need to be seated on a modern motor. From this point the motor is run in and all you really need to care for up to 500 miles is the trans and the differential. Occasional redline runs will do no harm what so ever past the first 1 or 2 hours of motor runtime.
I think they use what's called the "rolling road". There are many different definitions of these types of Dyno's and in Europe most chassis dynos are incorrectly called rolling road dynos. On a rolling road dyno the power applied to the rear wheels, in the case of the C7, also drives rollers on the front. This simulates actually going down the road so traction control systems can be checked. It also means the vehicle can be driven on the rolling road without strapping it down though I believe they have stops that pop up and engage the frame to prevent movement. Of course you can't do power pulls but they needed to find a way to test everything quickly and the rolling road gives them that.When I was on the factory tour as part of RedHot's Museum delivery, every C7 coming off the line went through a dyno set up including where they ran the engine up to 70 mph and completed somewhere in the vicinity of 600 electronic related tests.