Axle U Bolt Torque Specs?

I'm almost where you are, and I've been instructed that 45lbs is where you want to be for the u-bolts.

The leaf-spring needs to effectively "suspend", and cranking down too much prevents this, keeping the spring from working as designed (correct pinion-angle is very important to this function as well).

Tightening down too much will affect both traction and ride.