ported manifold. I port matched the head as well, there was like 1/8" worth of material that I took off all around the circle, increased the cross section by 1/4"! Amazing how mismatched the head and manifold ports were.
I only ported the manifolds slightly as the gasket itself was only slightly larger than the manifold (1/32"). My main concern was to make the manifold smooth internally to reduce turbulence. I also did the same with the turbine housings, but I could only get so far into them because of their shape. A dremel is a great tool for doing this, but you will need to invest about $50 in cutoff wheels, grinders, etc etc to do it. I certainly went through at least that much and it took a couple hours to do. Those cast manifolds are some tough puppies.
