On Tue, 30 Oct 2007 08:42:35 -0500, Ignoramus1285
wrote:

Larry, I googled "harbor freight" "truck crane" and there is a
consensus that the crane would completely mangle the bed.

Some some reinforcement is needed.

I am thinking about finding something like a 3/8", 16x16 steel square
that I could bolt to the bed, and then I would mount the crane on
that.

Not even that will do it. You will need to make a mount under the
bed that goes to the frame to carry the actual load. Beds are not made
to handle the kind of load a crane puts on it.

The mount needs to be something like a piece of 2 x 6 x 1/4w"
rectangular tubing (you need tubing not channel in order to handle the
twisting load). Run this across the top of the frame under the bed and
attach it to both frame rails. Then a plate on top where the hoist
mounts that is tight up against the bottom of the bed. At that point
you will need to make spacers to fill the grooves of the bed between
the plate and the base of the hoist. Then you can bolt through and
clamp the bed between the two plates.

The only other way would be to have a piece of 1/2" plate about 3 to
4 foot square to mount it to and then I wouldn't trust it for full
rated load.

More pain in the butt.

It's worse than that.