Were there 5.7l Vortec lubrication design changes?

[Get Bent]

I was talking to a gentleman about the 5.7l Vortec and what he thought about going from a 30 weight to a 40 weight oil. He told me that there were one or two years where they changed the design of the lubrication system and if you used a 40 weight oil, it would starve the engine of oil. Has anyone heard this?

 

[RED TAHOE LS]

5W20 OR 5W30, it's designed for either, 40w is not good for hydraulic lifters.

David g......