On Wed, 18 May 2011 19:09:01 -0500, Ignoramus15557
wrote:

Guys... I am not talking to anyone specifically right now... I sense a
little bit of B/S on this topic.

Right now, I have a crane that lifts 500 lbs, mounted on a 1x1 foot
plate, with angle iron underneath the bed holding it in [place with
thru bolts. While it is slightly shaky, it works just fine.

With this Ramco crane, I am going to have a crane that would lift
about twice more weight -- 1k lbs -- supported by a 3x4 foot
plate. That is 12 times more area than the 1x1 foot plate! Even if it
is not evenly distributed across the plate, it is still a hell of a
lot more support and weight distribution than a 1x1 foot plate.

I think that I will be just fine with it without fabricating any funky
adapters and bolting them to the frame.

i
I don't know the weight of your 5,000 lb. capacity crane or your
plate, but assuming that your plate is 3/4" and the crane weighs 500
lbs then you have a maximum weight of components plus load of 5,868
lbs. divided by 1728"2 = ~3.4 psi.

I just measured the area of one foot and weighed myself. If I stand on
one foot in the back of your pickup I will exert a force of ~5.36 psi.