Have a wee look into who actually makes all these engines, that Volvo and Mercruiser have used for the last 40 years or so, until fairly recently.
The 3.0, 4.3, 5,0, 5.7, 6.2 7.4, 8.1 and 8.2 etc etc. All GM engines. Maybe hold your smart opinion, next time it wants to get the better of you...