What size joint was it? Do you know why it broke?
U joints rarely break unless the yokes bind. According to Jesse at HAD, his 1350 CV can take all the horsepower you can apply to it and will not break unless hit by a foreign object or the angle becomes to great and the yokes bind.
If this was a Saginaw CV, 1330, or 1310, or an axle joint, I can see it easily becoming over-torqued by the truck though.
I suggest that you investigate this failure further so it doesn't happen again. /forums/images/graemlins/thumb.gif