The displacement numbers are the same and that's almost were it ends. The starters and transmissions are interchangeable. There could be others, but that's all I know of. A good friend of mine races Olds so I always joke with him about swiping one of his mini-starters. You can make a Olds fast with a small fortune, he is currently running 8.141 @ 163 mph in the quarter. But that's with a well built 425 and a tube chassis car.
