Right, Im over google and cant find what I am after. Can anyone tell me the spline amount of the pinion gear to yoke, what series uni fits the joint 1310 etc? from end of tailshaft to flange that bolts to diff flange and is this classed as the GM 8.5 inch diff? Basically Im going to run 1350 series uni's/yolks with the new tailshaft im getting built but dont know if there's a 1350 series yolk that will fit the Borg Warner or if I have to get a reducing uni (1350-1310? etc) to suit the the uni size I have now? I ask these questions as I recon i'll buy all the uni/yolks myself out of the states and have it put together here.