You really haven't given enough information to truly advise where your temps should be.
The type of thermal grease can affect ultimate temps, some of them like Arctic Silver 5 need time to set up.
Also, the airflow through your case, and the heatsink on your CPU make a huge difference.
If you're using the STOCK Intel heatsink that came with the CPU, I'd say you're normal.
The 51,48 numbers suggest that Core 0 and Core 1 are being used. The 39,38 temps suggest Core 2 and Core 3 are sitting at idle. With 39/38 as idle temps I'd say you're doing okay if you're using a stock heat sink. Good aftermarket heatsinks should get you lower than that with stock speed/voltage settings on the Q6600.