PC2700 RAM is ok for using with a 2.4B CPU. How much RAM do you have? If it's only 256 meg, then yeah, more RAM will definitely help. Nowadays you probably want at least 512 meg. Most of us here have a gig of RAM.
Regardless, as long as your temps are not excessive, go ahead and overclock that sucker. Go into the BIOS and look at the Softmenu page. Fix the AGP/PCI to 66/33. Scroll through the CPU clock speed options until you find "user define". The frequency (FSB) will no longer be grayed out. Try increasing the FSB from the default 133 to maybe 139 MHz. If that works, you should be running overclocked at 2.5 gig. Check temps and test for stability. If all is well, raise the FSB a little more. Again check temps and test for stability, etc.