Need diagram for 87 heritage softail oil line routing

The tank has four lines on it. The large line on back side of the tank is the oil drain line. The lowest oil line on the bottom of the tank goes to the feed side of the oil pump. The oil comes out of the other fitting on the pump and goes through the oil filter. It goes to the outer edge of the filter. The oil comes out of the center of the filter and goes back to one of the upper nipples on the tank. There is a vent line that comes out of the case just behind and above the oil pump that goes to the other high nipple of the tank.

If you can't figure out which fitting is which on your oil pump, jack the rear wheel up and put the transmission in high gear, remove the spark plugs. Then, using a oil squirt can, fill the fittings with oil. Turn the rear wheel in the normal direction of rotation and watch which fitting spits the oil out, this is the return side of the pump and the other side is the feed side. Depending on how the oil pump is set up, the feed fitting is the one closest to the centerline of the bike usually. But, It depends on how the pump is set up. If it only has one fitting on the pump outer plate, that is the feed fitting.

Good Luck
Steve