From what I have observed on unrestored/survivor cars, if it was equipped with a Dana 60, the leaf springs were painted black. Cars equipped with an 8-3/4 rear end could have come either black or natural, but I've seen more unrestored/survivor 8-3/4 cars with black springs than natural.

My car is a Dana 60 car and the leaf springs were definitely black from the factory. When I disassembled them for restoration, there was no black paint in-between the leafs, as Scott Smith stated. The tolerancing was too tight to allow the paint to flow between the leafs. Evaporust is the best method to strip the springs. It takes a little longer depending on how much rust is present, but the results are outstanding.