On my 81SD it sits on the rear of the ID, in that tight space between the IP and the filter cannister. Has just enough room in there to get your hand in there.
The 80 has a different engine, if I recall it has the 617.950, the 81 came with the 617.951 engine. I am not familiar with the 950, but seems I had heard it did not have a fuel rack damper? Not sure.