I made a valve removal tool out of a pry bar and was able to get the retainers and spring out. Next, I spun the valve with a drill, and then reassembled the spring and retainers. I then pressure tested and vacuum tested the intake runner and found that both values improved. This is an indicator to me that the valve will likely seat once the engine is running because of the explosions pressing against it.
It looks like I will be moving forward with final engine assembly and installation into the car.
Here is a photo of the tool that I made.