Don't worry about temperature difference between processors in a dual system.
Having dual CPU-s will always result in a different temp for each one of them (might be a C or two, or 5, or even 10) - it all comes down to your machine's cooling system and the way the heat travels throughout the case.
Normally, the one closer to the back side (left) will always have a higher temp since the 2nd one's hot air is passing through it's cooler to go out. I have a dual Xeon machine as well (E5) with quite decent cooling and in 100% load my left CPU is around 54c while the right one is at 47-49c mostly.
While idling, they are at 34c for the left one and 31-33c for the right one.
I guess that the only time you could have them at the same temperatures is if you cool them with water (of course there could be some slight difference since no unit is the same, different batch build quality, etc.).
Also, some motherboards have vertically positioned sockets (top/bottom instead of left/right) so these might have better airflow while using air coolers.
P.S. Sorry for my bad English :)
