The drawing in the AIM is poor at best and difficult to make out, but it's actually number 2. The Z/28, L78, L89 and L72 throttle rod fits in the SMALL hole directly below the LARGE hole in the throttle lever. (The LARGE hole that takes a black rubber bushing and white nylon sleeve wasn't used.)
Here's a picture of an unrestored Z28 (see below)
Ed