If you still have the stock oil pan put 4-5 quarts(allowing for filter) of liquid in it mark the level and measure down to and mark, that would be your dipstick mark.. You don't want the crank lobes to hit the oil that would cause a washing machine effect. If the windage tray is fairly close to the lobes I would think slightly below that is good. The windage tray keep the splash to a minimum and off the lobes.
