Even if it were a small block SS the "Z 27" would be on the tag of a NOR car of that year. I looked pretty hard at that tag to see a trace of anything in that area...my guess is that it's a standard 8 cyl. RS coupe (if the front end hasn't been swapped that is).
Rick and Ken just got my head scratching a bit though. What was the starting/ending(?) point of the use of BOTH Z27 and the BB code on the same tag?
I've seen them both ways but never factored build date into the equation.
Here's a 71 LS3 example that I had a pic of:
