OVERCLOCKING COMPLETE CONFIGURATION?

How much can i overclock my complete CONFIGURATION : CPU - Core 2 Duo E6850 (stock cooler), 4gb kingston ddr2 800 ram (2x2gb), MOBO : ASUS P5K, GPU: gainward 4850 512mb (ASUS - that gold and black cooler like on asus gpu), HDD - Maxtor ATA 60gb xD xD xD I know i know funny isn't it xD xD xD I need to know how much can i overclock every one of these components whit-out destroying them. Im not planing on changing my coolers because my temps are next, measured in a room temperature of 28 degree Celsius AND AT MAX LOAD : CPU - 59 degrees, MOBO - 42 degrease, GPU - 65 degrees ( idle its on 40 to 41) cooler is not connected with gpu but instead in that power cord for ATA hdd and DVD ROM ( i don't know how is it called) there are apsolutley no sounds produced by a cooler, thing is i cant control its rpm and i have no idea how much % are they turned on. My power suply is PowerLine 530w. I'm able to play Crisys on all very high but shadows that are on high and postprocesing quality set on high, this way i get about 40fps which is really fluid, if i set all on very high it goes around 25 - 30fps which is playable but i like to have a few more fps so i need to overclock. All advices will be welcome :)