Alldata is the probably most common source for multiple vehicle specs. It's normal for any mechanic shop to have access and computer for the techs to use. Before the magic of computers, shops like my Truck equipment shop had Thousands of dollars invested in paper manuals.
But it is crucial to use the instructions from manufactures. I remember Bell Tech drop spindles used to require a different fastener than the stock one and torque spec was much higher. Lean on your suppliers to get you proper specs in writing- your liability needs to be covered. When we would do one off builds for DOD, DOJ, DOT, etc we had to have stamped engineering plans for them. At one point we installed Timbren over load springs on around 100 mail trucks and the required paperwork jacked the price up to nearly double. Err on the side of caution.
As a retired mechanical design engineer, I have several charts available with SAE (and others) recommended torque specs per fastener sizes, grades, and types, but in your case, and as Will said, you need to go with manufacturer data for liability and safety reasons.
Welcome To the Truck Stop!