U joint Question

I could just change two of the bearing caps on the 7260 joint, right?

Without checking the dimensions book, I would not bet money on this. Very few U joints share the same cross, especially between Ford/ Mopar

Even "back when" Precision used to show three numbers in various forms of "heavy duty" all for the same Spicer application. I don't even remember only two of them (Precision 360 -- 369) but even though they all interchanged, the crosses were all different.