suppooooosably you can put wood wedges in to retain the spring/valves and pull the cam, turn the block over so the lifter is down,
so i've heard.... I wouldn't pull the cam without retaining or removing the springs.
A spare ford horseshoe clip wouldn't be difficult here to find.
....With that said and being one valve. Flip the block and use a valve fork to compress the spring. Then have someone pull the cam out. done.
or one of these...
.