[EdgecrusherXES]

For the application you have sticking with OE is best and here is why.
The engine oil squirters are specifically calibrated for the weight the manufacture specifies. Will changing the oil weight actually do anything or increase life of the engine likely not as the engine is designed to run the lightweight oil. Also modern engines are built to a degree of precision that your older engines just were not so they can run these lightweight oils to increase fuel efficiency even if it is just a little bit. Side note about oil weights if you run anything other than what is specified for the truck and you have a failure that requires warranty GM can deny the warranty repair based off incorrect oil.
I would not worry about oil weight but worry about maintaining the oil levels in the truck. These engines do use oil burning it off as it vaporizes and gets sucked out the PCV system.