Have you considered going right to a better head now? I didn't when i had the chance years ago and painted myself into a financial corner, and am now limited to 440-1 heads. You might want to sharpen your pencil and see what it would take to build what you want now, rather than after you put $$$$$$ in good rockers, the right cam, converter, gears, etc. In my case i would have gone with B1Mc heads if i had thought enough about my future goals. Instead I started with pocket ported heads, then had bigger valves and a full port done, and finally tried an even bigger intake valve combo. I would have some $$ left over had i done it right the first time.