Since the forum only allows 5 pictures per post, I posted a bunch more on my Web site. Near the bottom are pictures of the motor.
http://www.brassknux.com/z28/
Also, it has a clear title and has been garaged since I bought it this past February. It starts up on the first try and I drove it around Saturday night for about 30 minutes with no problems. The previous owner put in a new battery and said they had the radiator replaced as well.
Keep in mind that the speedo has rolled over once so it's got 99999 + what the picture shows.

I estimate it to be 157K.