Boss,
Try to measure the distance between the two attachment points from center of hole to center of other hole on the truck itself. If his old bar is no longer on the truck, and the truck is resting on the ground, then that measured distance will be approxiamatly the right length give or take 3/4 of an inch or so. If in the resting position, the rear is over to one side and not centered, then you need to factor that in so that when the rear is where it is supposed to be under the truck, then you take the measurement.
I hope I haven't made this too confusing. Let me know the measurement and I'll verify if the bar will fit.
Thanks,
72longbed