I wonder by early, if they mean the old cast iron gear box. think 80 was the last year for them, then they went to the one piece aluminium box.
I have both rods, not a lot of difference in the length. I suppose enough to make a difference
When I did my swap, I used the white rod. You think maybe using the longer black rod might but a little pressure on the MC, which would push some against the slave causing the release bearing to work harder.? Just a thought.
My peddle grabs close to the floor. maybe the longer rod would help have it grab a little higher. there really isn`t any adjustments to help much.
Charlie