That hand-crank "feature" (unadvertised/un-promoted by GM in 1949 and later, it seems?), was not available on harmonic balancers from 1953 or 1954 upwards.
In 1953, the belt groove changed to 3/8". The 1953 balancer might have had the hand-crank "feature".
A wider belt was used in earlier years, so if you use a balancer without the hand-crank "feature", you will need to change to a narrower fan belt. That belt will ride low in your water pump fan pulley (unless you change it) and in your generator pulley (unless you change it).
