I don’t think it should slide up and down that much it should allow for the distributer to turn but not go up and down .I think mine has a clamp on the advance but I see others don’t but maybe you the vacume advance is not on the distributer proper. I will check mine a little later . When you put the distributer in you can look down in the engine and see the slot for the oil pump and turn it to line up when you put the distributer in .(by the way did you prime the oil pump).
