mrrec, WEIRD? GM must have forgot to drill and tap the block in the machining process for some reason.
My 06A RSZ28 has the holes and engine was built VO527DZ.
New to me, i have never run across that before, and i have built and machined a lot of blocks in the last 36 years in the trade.
What are the casting numbers and date and the pad Stamp number?
As long as the block numbers match all your documentation i would not worry about it.
just my .25 worth
