9800gt green bios v-mod

hi folks.. ive just heard pcie v2.0 can supply 150 watts from mobo without any extra power cables from psu..

my graphic card is Sparkle 9800GT Green/Low/Eco whatever you call it.. its power saving things needs no extra power cable..
here is the pic of my beauty


and its linked with pcie v2.0 and shows its core limit is 652 mhz


also my mobo is Gigabyte ep45-ds3p
http://www.gigabyte.com.tw/Support/Motherboard/BIOS_Mod...
and i got zalman vf-1000 to keep her frozen
http://enthusiast.hardocp.com/article/2007/12/18/geforc...

which looks like this after settled it


i've got no heat problem so..

and i saved my bios with gpu-z and read it with nbitor.. here what it shows



as you can see its provieds 1.05 v at 3d mode which is lower than ordinary 9800gt with 1.15v~..

so my thought and hope, can i change 1.05 to 1.15v or more voltages and flashed her with new bios to overclock up to 750mhz or more core clocks.. can my card handle to run over her with more power than stocks without any harm ? or i just making it up and is useless idea that may cause to break my card? while vanilla 9800gt's has 4 phases, those numbers are 3 at green versions..

but i cant silence my wonder, it seems i will do it sooner or later.. lol.. it shouldnt need extra power right? 150 watts from mobo should be enough for her.. its not a Fermi .. the thing is card's circuits may show troubles to me.. but i think, atm it shows crashes when gpu is at 652 mhz.. after i push gpuv from 1.05 to 1.15 it may show crashes when its at 600 mhz if card doesnt deal with extra power.. am i right ? but whatif it works

i think i need a dx486 heatsink for vrm's before the operation



all my thanks and apologises for my short English..