Spicer part number is 5-4x. For what it's worth, some say that Spicer no longer makes them, other's say they are now made for Spicer but not by Spicer and others say that there is stock out there, just need to find it. Try asking for a 1993 Volvo 240. That's what I asked the guy at Advance Auto and he got me the PDQ/Neapco 1-0005 u-joints, a popular replacement for stock.
see:
http://www.lrfaq.org/RR/RR.u-joint_replacement.html
