When you are asked about original verses modified, think real hard about what you intend to with the truck once it is road worthy. If you plan on road racing, parking lot racing, drag racing, street racing, or just terrible driving in general, then yes modify it for yours and the safety of those around you. But, before going down that road, I strongly suggest getting some drive time in it to be sure you even want the thing. It is a truck after all. It will always be a truck, ride like a truck, and handle like a truck, and is nothing like a modern truck!
On the other hand, if you plan to drive it like it's meant to be driven, then stock is plenty good. Updating the brakes is worth the money if, and this is a big if, you are not willing to put in the time to properly mate the shoes and drums, and adjust for correct contact. Stock brake are more then adequate if set up properly.
As for steering, go here and read the shop manual,
http://chevy.oldcarmanualproject.com .
