The valves were really gunked up and corroded, along with the seats. There had to be a big loss in performance and power due to the air flow and poor seating. The picture isn't great, but this could be one of those ads seen at a gas station about gunked up valves:
I can't wait to see the increase in horsepower and engine performance from improving how the motor breathes. The heads after a valve job and painting:
Here's a before and after of the top half. This the top half of the engine complete and ready for re-assembly to the block. Looks like the car is being rebuilt in the guest room. Oh well, I'll just have to knock out a wall of that room and create a new garage bay so I can drive it out when it's done!
Now onto the firewall and block.