This is the exact same chip I have... L739A664
It's definately an interesting batch #. Eva has this chip as well and has had an awful OCing experience with it, I on the other hand am having a blast!

I've had it up to 4.6 @ 1.55v (load) stable enough to do some super pi and wprime runs, but it was nowhere near prime95 stable... this chip is capable of some amazing overclocks, but it's really hard to get prime stable.

I am currently testing at 4.15 (415x10) with 1.47v set in bios, but it drops to 1.4v under load. 2 hours into prime right now...

again, this batch (at least my chip) is capable of some amazing clocks, but stability on the other hand...