I have rebuilt a bunch of carbs. the only thing I have ever done was told my supplier whether it was a ma3,ma4 or ma4-5. The plungers have always been carb specific. I know every ma4-5 I have rebuilt has had the exact same accelerator pump in it. I don't think the part #(application) on your carb is needed for the accelerator pump. I would say some of the other parts, it would make a difference like : the idle jet and main jet or venturi.