Taking the differential out is not the same as taking the third member out. Only certain axles have a "third member". The most popular being the Furd 9" axle. The "Eaton" axle that we see on our 3/4 and 1 tons also has a drop out third member, but it is a MUCH less popular axle in the world of hot rods / resto rods.
Look at a picture of the back of your axle. Match it up to ID sights on the web.
