Quad Core i7 on E6420 XFR?

I dug around Google and found that the quad core i7 sandy bridge does work on the regular E6420. The question is if it will work on the XFR. The motherboard does look physically same, but I hear that the quad core and the non quad cores have different sockets? And that the dual cores can fit into any mobo with quads, but quads don't necessarily fit into sockets of duals?

Anyone have information? Trying to fit a i7 2670QM in replacement of the i3 2330M..

 

The sockets are the same.. It should fi and I presume work and the cooling system will probably handle it if it's decent enough (TDP difference is not that huge - 45W compared to 35W).

I'd say - try it

 

Anyone else know for sure if it will work? These CPUs cost a lot and I can't really return it!