RD RAM

Hi,
felt there would be someone out there with enough knowledge to solve my problem:
i have 2 pairs of rd ram 128mb(64×2 pc800) and 512mb(256×2 pc700). But since my mobo(intel 850GB) supports only pc600 and 800,all my rimms are running at 600 🙁 can you please tell me a way to overclock it to run atleast at 800 ?