I am porting my Gt40p heads. On the exhaust's I have run into a strange problem. I was porting the left side of the port, and I ran into what seems to be a pocket of white sand, or powder. I ported all the other exhaust ports just as far in the same spot and it is solid cast iron. On this one port there is a small inperfection with this white stuff in it. I didnt break into a water jacket, because I probed around in the spot, and it is solid behind the white stuff. It is really strange, I was wondering, since you have ported numerous heads, if this is just a cast inperfection or if it is something more serious. Thanks alot.
Ted
Ted