First card has more Vram then the second card and they are both the same. I don't know if it will. I think you have a clearence problem with what is on the back side of the PCIe slot. I really can't tell.
I know they make a flex adapter that plugs in the slot and the flex cable bends to put the card in another area. From the pic's the hardwear on the back side of the PCIe slot looks to be higher. But I don't trust my eyes half the time.
If it weren't for the piece of hardwear it would mate with that MOBO very well. Maybe someone else can see if it does. Sorry I do wish you good luck on this.