http://www.moparts.org/Tech/Archive/shaft/4.htmlfrom the tech archives
Lar, the 13.. joints you asked about are Spicer brand or "styles" of Ujoints, their specs are:
1310, End of Cap to End of Cap 3.219", cap dia 1.063"
1330, End of Cap to End of Cap 3.625", cap dia 1.063"
1350, End of Cap to End of Cap 3.625", cap dia 1.188"
The Mopar/Detroit joint specs are:
7260, Clip to Clip 2.125" or 3.125" EoC to EoC, Cap dia 1.078"
7290, Clip to clip 2.625" or 3.625 EoC to EoC, Cap dia 1.125"
Here is a pic of the 1330-1350 Conversion joint I am currently using for my Dshaft to rear end connection. There is a big difference between the size and strength between the caps of this joint.
Hope this helps.
Troy
