For anyone restoring or working on an old Mustang, here is a tip that will save you time and grief. A Factory Shop Manual should be the first thing you purchase.
This shop manual has step-by-step instructions on most repairs, including the specifications and tolerances for frame components, steering alignment, engine tune-up, engine clearances, bolt torque and more.
A shop manual will also give you the directions and guidance you need to install aftermarket parts when manufacturers do not provide thorough installation instructions.
The 1971 Factory Shop Manual is a five volume set containing an amazing amount of information.