Wow, those RARE GEMS from GM are all over the place. I have a rare ZL-1 convertible RS, but silly GM, they forgot to add aluminum to the engine mold, so they used iron instead, and only filled up the mold part way, so my all aluminum 427 looks similar to a 350 cast iron engine. But this only adds to the value of this particular car as you have the rarest ZL-1 ever. It's the only one that looks like a small block.