An "880" block may or may not be drilled for the coolant bypass needed on the TBI cylinder heads.
This is a double-drilling, one hole down from the cylinder head gasket surface, at a goofy angle. The other drilling intersects the first one at the bottom, and leads to the water pump gasket surface.
I have the sense that most "880" blocks do not have this double-drilling. I've seen some that do.
You must be registered for see images attach
You must be registered for see images attach
The matching hole on the water pump gasket surface is the reason that SBC water pump gaskets have the extra, smaller hole under the water pump outlet hole.