[PanelDeland]

Both manuals are worth having although they overlap a lot.Another good resource is the LMC catalog.They have lots of pics and drawings.Haynes and Chiltons also make manuals for these trucks.One of the things I have found is that the vendors on this BB will generally help anyone with assembly problems even if they did not originally sell the parts;go ask the parts boy at the Zone to do that.
That being said,I am a maintainence mechanic and will attest to the fact that manuals are the best source of info for most repair work.The better documentation you have on a project or piece of equipment the better your chances of being able to repair it.Even when dealing with factory tech support you need the "nomenclature"That is what the factory calls the part.If Chevrolet still had tech support for these trucks most of it would come from some fool that could work his way thru a computer program and he would follow a scripted troubleshooting guide,kind of like parts boy down at the Checker/Shucks/Cragen.