Your not gonna need the whole shaft other than the convenience if you twist one off. Where they break is right at the end of stub shaft, basically twisting off the splines by the lockout. I just carry a stub, if ya got the tools to change it in the field a u-joint isn't hard to deal with, especially the closed knuckle as they are never rusty, they fit either side. How many ya need, I got plenty of spares.
Abner-73 He started it all in 1979 (plow truck now)
Bufurd-69 Fixed up to take Abners place as DD
Delta-70 Built for fun, 455 Olds, T-18, D-20, 4:10 gears
Humpty-74 J-20 4BT, NV4500, 30+MPG
07 JK Wife bought new...
13 Grand Cherokee Trail Hawk, wifes new ride