Question about geforce boost and overclocking

so i have geforce boost enabled and have a water cooling setup. my 8500gt is overclocking exceptionally well however im wondering if overclocking the card is a bad idea. seeing as how i thought the chipset(8300) and video card need to have the same core speeds. whether or not this is true can i overclock the chipset to gain an even better performance gain and if so how do i go about doing it. Ive added a fan mod to the stock chipset heatsink so temperatures shouldnt be an issue for me. So far ive overclocked the 8500gt as follows:

core clock from 459 to 575
shader clock from 918 to 1155
and memory clock from 300 to 350. The ic chips let me know that 333 is a safe overclock so i went beyond that and ran ntunes stress test for 6 hours. I only had a 2 degree jump in temperature on the video card and no errors or artifacts using atitool's stress test. I also played needforspeed underground 2 for about an hour or two on mostly high settings at 1280x1024 resolution with no problems. Anyways any comments would be greatly appreciated. Also if you have any questions that will help you help me, dont hesitate to ask. thank you in advance.

alright so ive edited the 2 sentences above and yes you may be right about the excessiveness. but, its more for looks nonetheless.