O'K now i'm more clear, it is a sq. port, both the manifold you recieved and the manifold you thought you were getting are single plain manifolds. Don't sell it, trust me you will not know the difference in a manifold that's supposed to perform from 3500 to 8500, and a manifold that's supposed to perform 4500 to 8500. O'K it's not what you thought you were buying and i understand that point, but the seller did not misrepresent it in his ad. You still have an excellent manifold. With that said i donot run B/BLKs, i only build them for customers, but i would not hasitate to use that manifold.
JMO
Zip.