If only it was that easy. Casting requires huge amounts of up-front capital for the materials and equipment. Manufacturers of metal parts generally don't bother with it until they know for sure they'll be making a large volume. Just the molds alone are crazy complex, look at even our old-school blocks then try to imagine the "inverse" of that, made out of sand that holds its shape and withstands molten metal being poured into it. I'm FAR from an expert on it but just barely know enough to know it's not a joke. Reminds me of the story about the first 426 Hemi blocks made for NASCAR in 1964, just modifying the existing RB molds for thicker cylinder walls required several runs to get them right.
