I know the wheel will bolt right up to the column, but am I going to need any extra parts to make the horn work? thanks in advance.
should be able to get the modern horn contact ring to work with it, the little protruberance with the spring has to go through the hole in the steering wheel. Knowing what exactly you mean by "late" would help us help you, of course.
I'm using an '58 to '60 Impala wheel. The horn stuff is the same as the 70's - 80's era GM squarebody trucks.
Outside of figuring out how to get the horn to work the other and bigger issue might be the diameter (s) of the steering wheel hub and the column. Before I let go of any money I would want to know what the diameter of the turn signal housing is on the column and compare that with th 56 wheel.