Purchased a brand new 2021 Chevy Silverado HD with the 6.6 gas engine and drove it home from Paris Kentucky to Miami Florida. Enjoyed it for a few days until coolant was seen leaking from the passenger side cylinder head. A trip to my local dealer confirmed that the cylinder head needed to be replaced. The service manager informed me that the part had a "back order status with no eta". Dealing with GM corporate is no easy task… they are no help at all. Truck purchased May 8, 2021 Truck at dealer May 20, 2021 It's June 2, 2021 and there is no resolution in sight.