Abstract: A convertible boom is supported by an upstanding post and base frame. The boom is provided with appropriately located connectors so that it may be attached to the upper portion of the post to form a hoist or it may be connected proximate the bottom of the post to create a jacking device. In both cases, a portable jack is used to actuate the boom. The end of the boom may be equipped with a rotatable and tiltable cradle having extendable arms. The upstanding post may be provided with a rotatable workpiece mount which includes a plate having a plurality of outwardly projecting pins which extend through slotted connector rods. The rods can be arranged in a variety of positions to facilitate connection to a workpiece.