I’m not gonna argue model year stuff, obviously stuff gets cast well before it hits the line and the next model year cars are built for like 5 months in the prior calendar year and those years I listed are just general model year ranges from the internet anyway.
Factory head CC’s vary quite a bit with all that stuff, my 308’s were uncut and ~65cc’s as cast, but most are probably closer to 72cc.
With all the aftermarket heads available now and the price of then I don’t think I’d even bother rebuilding a set of used factory heads anyway. After I had the 308’s checked for cracks, larger valves installed, ported and cleaned up I had as much or more money into them than what it would cost to buy an aftermarket set of heads and have them checked. Only way factory heads are worth it is if they’re required for your class or if you’re doing all the work yourself. Beyond that your money ahead with aftermarket heads and saving weight too. That was true 10 years ago when this thread was originally posted, and if anything it’s more true now with all the new cylinder head offerings that have happened since then.