So I spent about an hour or so changing the differential in my 8 3/4 housing and noticed when I went to put my u-joint caps on that it seems this particular yoke does not have threads???

Are there two different styles of yokes that take two different types of u-joint caps?

Seems that I have seen some before that were u-shaped and threaded and went through the yoke but the ones I had were just caps with 4 small bolts. It doesn't seem like mine have any marks on the back side of the yoke where nuts have been tightened.. Help!!!