Yes drilled and tapped to 1/2 NPT. When you chose a pump it may need to have the center moved over toward the thick wall of the pump. You can use a small grinding stone or a burr for this. Then do the drilling. I have found the newer pumps have been changed an don't have as much material as nthe older pump housings. I use the older ones for this modiflicstion. I have not measured the thickness around the hole but I will.