I found this on Rockauto.com.
Brembo now has their own aftermarket 2 piece ZL1 rotors. They look identical to their same 2 piece rotors they supply GM with.
I have purchased them and they have the same vent design, vane count and the same hat and fasteners The finish looks the same.
BREMBO #09A66513 Left
BREMBO #09A66523 Right
Prices sometimes change on RockAuto, but they are currently about $170 each, compared to the GM sourced Brembos at about $290. Also rockauto's inventory changes. As of 4/27/21 they only have the LF rotor. But shop around you can still find them for good prices.
It is possible that the cast iron is different, but everything else looks to be the same. As I mentioned, I have purchased a pair . I track my '14 1LE with the 6 piston front brakes and have no reservations with using these on track. They very well could be 100% identical but without the GM price surcharge.
https://www.brembostoreusa.com/produ...rotor/09A66513
https://www.brembostoreusa.com/produ...rotor/09A66523
