Thanks for the info.The 3400 came in both socket 754 and 939. It wasn't called a XP. It was just a Athlon 64 3400+
I think he means that he owns the 3200+ but the box of the heatsink indicates 3400+.
Socket A will match Socket A so the HSF should fit/function. The other Barton XPs had similar TDP so really most of anything will work. How high of an OC do you have on that 3200?