if i were you, i would try to find some 327 corvette "camelhump" heads. just portmatch those, and they should be good for up to 450 hp no problem. unless if your going for 700 plus, it really doesnt add that much more hp with even the most radical port and polish. sometimes if you get to durastic, you can hurt performance. just like putting to big of an intake on a car, it will decrease the performance unless if the motor is built for it. and if you plan on doing it yourself, its a risky thing. you have to get each chamber identical, each runner with the same CC. the only way to measure that is if you have all the plates and burettes and stands to measure all the volumes. if you just go in and smooth out some of the ridges that are left from the casting that should be good enough. maybe where the valve guide is, smooth to increase flow around that. other than that i really wouldnt do to much unless if you really know what your doing.