I did a CR bump to 13.5 and bump the carb from 600 to an 800 and got 300hp out of both 256 and 262 but 270 went to 290hp, 256 cam would be my choice just has a way better torque curve with very little loss in top end 6000-7000rpm
I find it interesting that you are finding out what everybody has been saying all along. That the head is the cork. Regardless of how well you can get it to flow, the stock head just doesn't have it in it. Interesting to see your computer program backing that up. Thanks for doing all of this for us. I appreciate your time.