u-bolt torque?
 

Does anyone know the torque specs. for the rear u-bolts on a 2006 f-350 srw?:-huh

I've been told they stretch. The Chevy's I've done were in the 250-350 ft-lbs range and a pain. The Fords I've pulled were about half that and much easier to undo.

ReAX is correct, the u-bolts stretch (torque to yield) and are one time use, so please do no reuse them.

As for the torque spec... The final spec is 148 lb-ft (200 Nm), but this should be done in 4 stages while using a cross type tightening pattern. The vehicle should also be on the ground and under its own weight while torquing them down. Just snug them while it is up in the air to get you started...