Original review updated by user Jul 22, 2021 I purchased a new 2021 GMC Sierra 6.6L. On the first oil change the dealer found a crack in the cylinder head. An obvious GMC quality issue. My truck has been at the dealer waiting for part for the past month with no follow up from GMC customer service as to when the part will be shipped to correct the issue. They tell me they will call in 2-3 days and nothing is happening! $750 truck payment on a truck I can't use! User's recommendation: Don't buy new! GMC will not take parts off the assembly line to fix your issue if you have one.