If you put the oil drain below the oil level the oil would not drain back to the pan. Follow the directions and put the fitting where they ask you to, if you don't like the idea of the tab you can pull the pan and weld a bung in.
Pack the tap full of thick grease, this will keep most of the debris out of the motor, flush it out, drain the oil and your good to go. Make sure you do not go to big with the punch or you'll have issues...
OR
Buy an ATI that is self contained, no oil return at all