you do not need o rings at 14to1 with a felpro1027 or 1017 gasket or any of the plate fel-pro racing blue gasket do not use the oem blue felpros you will blow the fire rings out . if the fire ring is ahead of the old o ring grove or in back your ok if the head gaskets cross the fire ring and hangs in the o ring grove in the block you can use a bigger bore gasket like a 1057 .thats the only thing i would watch out for if this happens you could use copper wire in the deck.BUT if it hang the head up off the deck the heads will leak water .so you need to know the O ring groves are the right depth.then you could use your head gaskets or deck them out re work the pistons or use a thicker msl gasket like cometic