I am getting my engine rebuilt with the howell top and bottom end kit along with 2mm oversized ferra valves and lots of headwork. Just for your info and I know alot of people want to know about the stock cfm readings. From his flowbench the stock readings are 277 cfm per port. By the time he gets done it will be around 320 per port with a curved valve job instead of a 3 angle. Supposedly it makes the engine run smoother becuae of the less distortion of the airflow.. Now if my engine ever gets done i will be happy. It is going on 6 months now..