what can i say. the canfields are very good heads but to build it with the 310 runner i would try to get more cr i see that they have a cnc 113 ?? head .run this head and hand fit the pistons by cut out the chambers 'not to much' for the dome and then cc the head you this will cr get it up there and run the the cam i said i like .but check for piston to valve on all piston