Actually, the one I bought did and it was for a B-Body as they didn't have a drop in A-body one at the time. All I had to is cut down the D Shaft. Other than that all the wiring adapters, floor plate and factory mount it dropped it. I love it, downside is you need a GM steering wheel or adapter to an aftermarket.
But I hear what your saying, most of this stuff is anything but painless at times.