RockAuto, CarQuest sometimes carries that brand, local truck shop supply places... we have Inland Truck Part and Godfrey Brake out here, both of them carry Spicer u-joints.
I am fairly sure the part you need is DANA 53215X (Front Axle at Wheels; 4WD; with Cap Diameter 1.062 IN; with Inside Snap Rings; with Snap Ring to Snap Ring Dimension 1.629 IN )
so get everything dana then? well I suppose the axle would be anyway no matter where I get it wouldn't it be? and should I replace every one of the ujoints? I'm certain I should... and I don't mind taking apart the axle assembly at the wheel... I think it kinda fun
... do you think Napa would carry Dana... I guess I can call and ask