Thanks everyone. The sump is ready to go. Just gotta dremel out more space in the stand (while the tank is still on top of it - yeah, fun). For some reason the holes for the returns were drilled right next to the edge of the cutout in the stand. The bulkhead fits through but there's no room for the nut to be tightened without hitting the wood. I have no idea how the previous owner managed to set the tank up... must've had 1/4-1/2 inch hanging off the back end of the stand. Terrible design.