When using any mechanical device there should be A wired Safety sling used in potential of device failing.
Chain block is require for alignment & fit-up prior to release the sling & crane. the important is that SWL of the chain block is to be consider while using it for such purpose.
In order to have a balanced lift, you need to know the following Weight of object to be lifted Center of gravity Number of attachment points Hitch type Geometry of lift including sling angles Reach Clearance – any height restrictions Upper and lower fitting requirements Ambient conditions