Wanting to overclock dell vostro?

[soook]

Vostro 400, Intel Core2 Quad Q6600 (2.40GHz, 1066FSB, 8MB L2)2GB DDR2 SDRAM 800MHz, Dual Channel DTDell USB Keyboard128MB NVIDIA GeForce 8300GS DVI/VGA160GB Serial ATA Hard Drive 7200RPM, 8MB CacheGenuine Windows XP HomeWindows XP Home backup CDCyberlink Power DVD 8.0,with Media, for Dell VostroDell Resource CD, Vostro 400Dell Scroll MouseIntegrated 10/100 Ethernet16X DVD+/-RW DriveIntegrated 7.1 Channel AudioDell Hardware Limited Warranty Plus Onsite Service Initial YearWarranty Support,Initial YearCan i OC this @ 3 ghz with stock cooling? I can buy a new sink/fan thats no problem.I'm also getting a new gvideo card for around 100$ should i go 9600GT or 8800GS