the original 4.8/5.3/6.0/6.2 LS engines are a fantastic replacement for the old 5.7 and other displatement block engine.
it wasn’t until they overloaded them with worthless tech like “active fuel management” that they started to go to hell. Couple that with an engine oil recomendation of thinner than water oil and less than perfect machining and you have...
The current problem.
Yup, my advice: Never, ever, use an oil with a viscosity that begins with ZERO, as in 0w=30.