Cast alloy type,this intake manifold for twin 1.25"SUs (H2 or H4 -- NOT HS4)
It has been carefully produced to minimize cross-port-flow interference caused by the balance tube and has generous radii in all the right places. Further blending can be done if required, but leave a ground finish to promote fuel atomization. Do NOT polish!
Same stud hole distances as original  manifold with casting number as fitted to Coopers but does not have recess holes for collars to head as per original.