I disagree with J. I think you can turn those into a great set of heads. After all, the problems with the spring seats being cut too low into the casting prevented raising the port roof for better flow, valve seats falling out and the guides being wrong size will not be your problem. The only thing I see wrong, is they are already cut for pushrod clearance, too bad they did not leave that alone. The other issue is having to run intake spacers on a RB block.
Good luck and keep the rest of us posted on your progress.