so update :
Dumped the vbios with gpuz.
Used kepler vbios modder 1.27
Changed the core clock/boost clock in the first page (+135Mhz to reach clocks I'm sure they work as i was using them before) and mem clock, and boost (+25.5MHz only cause I already have enough core clock) in the second one.
Flashed and rebooted
Result :
Mem clock are okey but the core clocks didnt worked, the gpu act as I changed nothing, and when I tried to reach OC it crashed..
Laptop : ASUS G750JW : i7 4700HQ - 16Gb - 2Tb HDD - GTX 765M OC (+135/500) - Full HD Matte - Win 8.1
Retiered : Toshiba L670 i5 560M/8Gb Corsair/1TB/HD5650 1Gb @ 625/800 /WD 1Tb USB3/Win7
