You folks are missing it. According to Spicer the 5-4x U-joint (the one for DII front propshaft) is not made by Spicer. They buy them from other companies. As I said in another thread, this probably explains why some people have seen them with zerks in the end caps (probably made by Neapco for that batch) and others with the zerk fitting in the valley (made by who knows who for that batch).
Spicer does make their other u-joints. Which isn't to say they make all of their other u-joints, the 5-4x is the only one I asked them about.
Neapco u-joints sold under the PDQ label are mostly not made by Neapco, they are bought from other companies (like the way Spicer gets their 5-4x joints). However, the PDQ 1-0005 is made by Neapco because it's small volumn and they don't farm them out.
Neapco boxed u-joints are made by Neapco.
As with many things you can't make blanket statements about who makes what. You have to speak of the specific item, not the entire line.
This is what I did when I called Spicer and Neapco, I asked about specific u-joints, the 5-4x and the 1-0005.
I can't think of any reason Spicer would tell me they don't make the 5-4x if they really do.