r2m
Richard
As a mechanical engineer, I too have some issues with the strength of bolt on components. It's not as if I don't think it can be done, it just as to be done right. Saying that, I would think that the proper way to execute this would be to have maybe 1/4" plate for both the pad on the bumper and and 1/4" plate for the mating surface on the stinger, upright, tubing (whatever). The 1/4" plate would not be the entire length of the top of the bumper, but just the contact points of the mating surface to prevent bending and sheering of the bumper top. Maybe use a bolt like this: http://www.mcmaster.com/#90909a534/=w6i4hp where you could get some strength and yet not look too pieced together.
Just my 2 cents.
Just my 2 cents.