Over clocking my 8400Gs Geforce EVGA

OK I got a Nvidia EVGA Ge-Force 8400gs
I can Over clock it With MSI AfterBurner.
It tells me that i can only OC three things
Core Clock
Shader Clock
Memory Clock

This is Factory settings
Core Clock is 567MHZ
Shader Clock is 1400
Memory Clock is 400

Do i need too OC my Shader Clock sense its all ready at 1400mhz.
Or do i just need Core and memory.

 

Core Clock is Normaly Set at 567Mhz
Shader Clock is Normaly Set at 1400Mhz
Memory Clock is Normaly Set at 400Mhz

I can Set
Core clock too 740Mhz
Shader Clock too 1820Mhz
Memory Clock too 520Mhz
these are the MAx settings and my temps Stay Around 150F on the GPU If i play a high end game Like GTA and it really stays around 150 or so

But Do i need too Set Shader too max if i got the Core clock and Memory Clock All ready too the max.