Well as it is, by my reckoning you've got a little over 2 cubic feet worth of internal volume per cabinet.
This could work fairly well, achieving a Qtc of 0.707 in a bit under 2 cubic feet, leaving some room for additional bracing. If I were inclined to get my hands dirty, I'd gut the cabinet, brace as needed, and install a new double-thick baffle, which would allow you to recess the driver a bit to achieve adequate clearance with the grill. With some signal shaping, it could turn out reasonably well.