Jack up the rear of the frame, and let the rear axle hang down. If you're supporting the weight of the vehicle with the axle tubes, or the weight of the the truck is on the tires, the shaft will be at its shortest point. With the rear end hanging down, the distance gets longer. Only an inch or two, but just enough to make the shaft fit.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!