That is great to finally have it explained. That would explain the odd emblems on the quarters and lack of a domed hood when compared to the normal 396SS cars. I have a domed hood at home waiting for paint but am not in any hurry to put it on. As best we can figure it was a 283 powerglide car. My dad bought it 16 years ago with the 396 and powerglide, then we turned it into a 4-speed car and I got it off him 6 years ago. It's still waiting for some proper gears and a posi in the back but until then, it sure makes the right noise.