If i had to make a guess....
It looks like the bosses are there for a hemi. By leaving that row undrilled, that block can still be used for a hemi or wedge.
As i said, a guess. I cant tell if the block is relieved for hemi pushrods.
That might be true but I think the OP thought he was buying a wedge block so the assumption is that it would come properly machined so he could bolt on a set of wedge heads. Someone at the factory will know what the issue is. My guess is that someone mixed up the CNC programs and that block got some wedge machine work and some Hemi machine work. If so there is some guy at the factory right now who is sorting thru the CNC programs trying to figure out what happened and how many blocks got screwed up. Glad it isn't me!
