needs help with my build

[Nour154]

for now i have desktop with :
motherboard : gigabyte g41 combo
CPU : intel Pentium 4 3.40 Ghz ( 1 core if i am not mistaken )
GPU : Nvidia GeForce 8400GS 512Mb
Ram : DDr2 3GB
Power Supply : 350w
and my monitor View Sonic VA1932wma i believe 1440x900

but i have intel core 2 quad q9650 and ddr3 1333mhz 8gb i bought weeks ago and rx 480 8gb
is my specs good and do i change the gpu or use another one other than rx 480 ?
i need tips