cMP swap single processor tray for dual

I've got a mate who's got an old unused 4,1 with a dual processor tray that has 2x 6-core 3.33GHz X5680s on it.

My 4,1 is the single processor version. Is it possible to use his tray in my computer? Will it cause problems or issues, or just run relatively okay? I assume I'll need to flash the firmware?

Thanks