Does anybody know the differences between a non-EFI fuel tank sending unit from an '86 Sport Coupe and an '84 Sport Coupe? Or, can somebody tell me if the fuel pump on an EFI sending unit is free-flowing or not? I'm going from EFI to carb and if I don't have to replace the sending unit, I'd rather not spend the $175 if I can just re-terminate the feed line and have my mechanical pump suck fuel through the inactive pump in the tank.