FYI - C9OE and D0OE 351 heads are the same. D0OE heads were used up through 1974 and are often found on family car engines like station wagons and stuff most 'yard pickers overlook. I've found several sets that way for cheap $. Since a careful search for aftermarket heads can bring new sets for under $600, you may want to get pricing for the machine work and figure your time and porting costs. You may find it's actually cost-competitive and less hassle to go the aftermarket route and likely getting better flow to boot.