Very rare sbc magnesium cross ram  manifold as used on the Corvette Grand Sport with 58 MM Webers.      These manifolds were designed by Chevy for use on the Grand Sport with side draft 58 mm Webers. later made by MacKay and  Mickey Thompson.   A couple were converted to fuel injection. One was used on Bruce McLaren can-am car. These manifolds have large ports like the biggest Chevy heads  The  adapter plates and short horns are available to convert to F.I. . The plates need to be drilled for butterfly shafts.  I am selling the manifold only other pictures are for reference only.  This manifold has the Chevy part number cast in.     contact    805 298-3152