Lynn,

I think the ultimate idea for a plate type mount is to use a drawn steel shape with indents for the lord mounts. Making the tooling for a short run for hydroforming wouldn't be that hard, and you make 20 as cheaply as 1. I would make the part the oil pan as well to save weight. That way you don't have the multiple gasket sandwich problem. Since the RX-8 pan is so shallow it would be an easy form. A bit pie-in-the-sky, but it would be a very elegant solution. Dry sump  inlet and outlets could be easily brazed on ...

Bill Jepson