I have a 939 socket mb which I had to remove the brackets and the backplate to mount a Zalman.
Then I went to the AM2 socket and bought the Arctic Cooler 64 like yours. It was just my recollection that AMD changed the AM2 stock cooler from the 939.
I am now running Core2 Duo so I don't remember exactly what happened with the AMD stock coolers. But I knew my Zalman for 939 would not fit the AM2 socket.
What 's the harm of trying?