The fact remains that GM would not have spent 10's of millions of dollars on R&D if the original LB7/LLY block, pistons, rods and other things were "good enough" for the "same reliability". It wasn't.
When you beef up things like block casting and rod size they were worried about reliability. GM missed it when they went from a 150 HP N/A 6.2 to a 200 HP turbo 6.5. It showed. All of the main webbing started to crack up and reliability suffered terribly. They leaned a lesson in that engine and they didn't want to repeat that mistake.
This is not to say if you add a 60 HP tuner to a LB7 it will blow up? It won't. Will the reliability be the same or better than my LBZ? GM say's no way in hell and so do I.
