Hi guys....wanna find out more which batch of C2d is more OCable... Which batch is reliable for the 6300 and 6600?

I went LY today and enquired a few shops...they have L627A (week27) and L629A (week29). Didn't come across a B unit yet....is there a difference in OC a A or B series? I only asked 2 shops for these processors..didn't have much time..