And is it ok to put on/use on a 5000lb truck?

http://www.jeepaholics.com/tech/quarterellip/images/Image10.gif

looks like a 4 link with straight lowers and triangulated uppers with 1/4 eliptical leafs holding it up.

this could be run on nearly any vehicle given proper design.

1/4 ellipticals were common sevearal years ago. Now people have swayed away from them for more blingin options

heres a heavy truck with the same set up

last i heard it was still for sale from the 2nd owner

I ran quater eliptical on my FJ40 and it was heavy with no problems at all.