Working on a set of B1 heads for this years build and trying to get 10-15 more CFM out of them so I poured a port mold so I could see a nice 3D mold of where I was at this point. I rarely pour anymore but being this is for a heads-up build if its there I gotta grab it. Very easy to do at home for the home head porters and I think this would help some if you never tried it. Here is a link of the place I deal with. If you order some talk to a tech and DON"T forget to order a spray can of "mold release"