Is there a difference between the socket 939 and 754 backplates? The reason I ask is that I have a Zalman CNPS7000A hs/fan. It's an older model and doesn't have instructions for the 939. It does, however, have instructions for the 754. I eyeballed the 754 adapter and it looks like it'll fit the backplate, but I thought I'd ask to make sure before I get knee-deep into this build.