I have a 1988 Seaswirl Sable with a OMC 5.7 liter engine in it. The fuel pump, Carter 981650, stopped pumping gas. Everything lead me to the replacement pump, 385527. I ordered the pump from IBOATS and they said it has been replaced by the Sierra 18-7268. I received the pump in the mail and the fitting for the lines are positioned differently and the line that goes to the carb (vent) does not appear on the pump. Is this trully the replacement?