Alibaba, I strongly disagree.
All pre 1985 R45 and R65 share the same crankshaft which gives a shorter stroke than the R75/80/90 and 100.
But after 1986 all airhead no matter which displacement, have the very same crankshaft. As they produced a full range from 650 to 1000 displacement, .... the crankshaft should be the same
You can check, if you want, with the part number for the crankshaft before and post 1986.
It is obvious if you actually look at the bikes. "old" R65 have a smaller engine than "new" R65....
As I doubt you had a lot of R65 made after 1985 in the US or Norway I understand you can be mistaken ;-) But given the number of such bikes one see in ex police junkyard in France, you've to be very cautious when buying parts for an 1982 R65 ... Otherwise, you have to try to make the junkyard owner give your money back... Guess how I know ?
P.S. : the "new" R65 is a real dog. The police complained about it in France, and, as the French customs officer where given the quite identical R80 but more powerful and a joy to ride, they complained more and more, and, finally they had new bikes more powerful ....