It's unlikely that you will find a "factory" power steering for a TF truck in a wrecking yard. It was an option but few were installed.
You can obtain a Saginaw gear box from a 67-87 truck and purchase the adaptor kit from a variety of suppliers.
Another option is a Toyota gear box from a 84-87 4X4.
In each case you will need to do other mods, tie rods, pitman arm, drag link, column, shifter, mount brackets, etc.
A column that is commonly used is from a 72 Chevy van/panel truck. You can use your existing key switch with this application. You can also modify your existing column and retain your existing shift arrangement.
I have done several of the Toyota conversions and the only component that may be availabe in a wrecking yard would be the gear box. They are also scarce since the word is out about their use.
Fred
