Me thinks 82 and 83 same...NLA, 84 500 available but longer, by about 12mm I think.
I have been down the road of fitting a 84 rod to an 82 with spacer under bottom of cylinder, only to find exhaust port was raised to high and was half blocked off by frame main front down tube. I should have taken $750 out into the back yard and burnt it, would have saved me two months of flucking as I ended up reusing the old rod....