Have a bare Block searching a value.
People will probably want to know some condition details.
Is there a vin on the block?
Like any more common engine blocks, condition and history will decide the value. Great condition and stock bore, will be more desirable then one that's had repairs, modifications, bored cylinders, etc.. And if there's a partial VIN, and the owner of the vehicle it belongs in is interested in buying it, that's another reason the value may increase,...in that guy's eyes anyway.