[gtofreek]

I've seen factory block decks range anywhere from 10.220"-10.250". Earlier blocks are taller. I've had to take .015" off some blocks just to get one deck cleaned up, and the twist taken out of it. We have to keep in mind that production engines are done on an assembly line in jigs, that work off of the oil pan rail, not the main housing bore. We deck blocks off of the main housing bore to get both decks square to each other, and the mains. On production blocks it is not uncommon to get a metal chip or a burr that prevents the block from sitting square in the jigs. This can result in twisted decks, height differences from front to rear, and side to side. Production blocks are far from perfect[contrary to some popular belief], and Pontiac's are no exception. Some of the worst decks I have seen where on Pontiac blocks.

So, yeah, there is no norm.