My computer is old and acting up so no copy and paste, just google search u-bolt torque. Most all the spring manufacturers have charts on their web sites. Torque values are for the thread diameter, doesn't matter what they go on. 1/2"-20 u-bolt for example, torques to 52-70 ft lbs depending on if its oiled, dry, or plated. After some drive time, they need a re-torque.
