Overclocking help for AMD Phenom ii x6 1055t.....!?!

[mandeep148]

i have overclock my AMD Phenom ii x6 1055t at 3.7 is stable.
Ram. Corsair Vengence 4gb ddr3 1600mhz,
Mobo. ASUS M4A78LT-M.
PSW. Cooler master extreme power 650watt.
heat sink: cooler master hyper 212 evo.

now i want to overclock my at 4.0 ghz.
Now my bios settings is
cpu bus 295x 13x multipler=3.9ghz
cpu overvoltage 1.54v
dram freq=785mhz is shown in cpu id.
dram voltage=1.65v
dram timmings=9 9 9 25 41 1t
ht/nb link 2065mhz.
vddnb voltage=auto
chipset voltage=auto
load line calibration= auto

i have check stability test with prime95 but only stable at 1hour,after 1hour prime95 worker says fatal error...
max temp is 51c.
so,please tell me what to do for reach stable 4.0ghz...

 

[mandeep148]

is there any body who can help me??