When the sucker rod is pushed down as far as it will go, there are about 5 inches of sucker rod protruding (left). This is the same amount of protrusion seen for the piston rod relative to the top edge of the pump cylinder.
As we continue to add all the lengths of sucker rod and drop pipe, the goal is to maintain that distance between the top of the sucker rod and the top of the drop pipe.
To get this result, try to have about 5/8" thread engagement between the female and male pipe ends. To achieve this, screw the two ends until hand tight. Then, using the two channel locks, screw one-half rotation furtherno more.