Can't the OP downclock the memory, and increase the front side bus frequency? I don't know if B series boards allow the FSB clock to be adjusted as I'm not much into Intel, but on a locked AMD chip, that is what you do.
But make sure that the memory is downclocked so that it doesn't exceed the rated spec on the RAM, or it won't boot, and it's a pain to reset.
Also, my standard warning: Be very careful when you OC as you can damage your hardware if you don't know what you are doing.
Remember: If you can't afford to replace it, don't OC it!