o deck the block . 16 cc may happen on the heads i set them up on the mill and cc them and cut them and re cc them . you would have to give them a cut to know. i can not tell you much on this. not seeing any thing but i think i wound go at the block i would say you have more than 17cc right there just did the big valves in a 402 head 113 is now 103cc with a .015 cut and the big valve allmost all the time fill up volume less they are sunk