You can't use two FX-60's on a dual-socket motherboard. Only Opterons can, which is why they are labeled 1xx, 2xx and 8xx. 1xx is for uniprocessor systems, 2xx is for dual-processor systems, and 8xx is for 4-8 processor systems. However, only Opterons have those links. Athlon's dont.
Which is why Opterons are so awesome. Imagine having a server with eight 8xx Opterons...that's 16 physical cores!
Yes, 8xx Opterons are dual-cores.