iMac 27'' logic board replacement

Hi everyone,

I own iMac 27'' mid 2011 i7 3.4 GHz

HD 6970 2GB

HDD 1TB

16GB RAM

My logic board is dead, I need new one.

So after some research on the internet i found that I need 661-5950 board, and also that compatible one is 661-5948?

Can anyone tell me can I go with 661-5948??

Any advices, comments, help?

Best regards

Dzenox