In case anyone else experiences this, I'm posting the solution to the problem I posted. Turns out the push rod became unseated on the back side. There is a bolt behind both valves that secure the valves to a plate. The bolt on the Intake valve had worked its way out an 1/8 inch. I think this loosened the valve enough that the rod became unseated. I tightened the bolt, re-seated the push rod and tightened valves according to specs using a feeler gauge.