Where is a speed sensor located on 1985 z28 camaro with 305 engine?

On a 1985 Camaro Z28 with a 305 engine, the Vehicle Speed Sensor (VSS) is located in the transmission. Specifically, it's on the output shaft of the transmission, usually near the speedometer cable connection point. You'll likely need to get under the car to see it. It's a fairly small sensor.