How interchangeable are 318 harmonic balancers?

Why so many spacers? Did the dude have the crank pulley on backwards? I would think that with the crank spacer, the wp pulley and alt mounting would all have to be modified..........Wouldn't that push the fan into the rad?

Edit........Maybe the WP pulley is the old style for a cast water pump which would be more shallow, necessitating the crank pulley to be spaced outward?

Sorry, just spit ballin'