Don't know if the Xfire connection will interfere, otherwise you will need to take away the cable between the cards.
Run two instances of cgminer and specify each card to a different pool,
cgminer -d 0 -o spt.pool.com ....
cgminer -d 1 -o gdc.pool.com ...
remember that cgminer removed support from gpus from version 3.8 so you must use 3.7.2 or earlier versions.
Excellent. Thank you