your ram is "value" ram which is not going to offer you much in the overclocking world surely you will never see a 15% OC
overclocking ram will be capable of more voltage than 1.8 volts (more like 2.1 -2.2)
and timings of 4-4-4-12
you could sell your existing sticks off on ebay and get some corsair XMS DDR2-800 PC2-6400 CAS4 memory then you will be ready to spice things up a bit