trailer-made-scratch becomes boneified tool

[Frank S]

It is only a half ton truck so it will need a drop leg for sure. I would prefer not to use a receiver hitch as I often have a trailer on as well. I have an 8' box but I really don't want to waste any on a crane. I bought a couple of small cable cranes, a 3 and a 5k lbs a couple of years ago but have not done anything yet. I was thinking I could use the passenger side of the frame with the receiver hitch bolts to get a sturdy attachment platform. I need the tail gate to be fully functional.

Ok here is one thing you can do that would not require loosing the factory bumper.
you would only have the crane on your truck when you needed it
The picture shows an attachment which connects into the receiver hitch sold by Jegs high performance centers. But you wouldn't necessarily want to use the receiver itself you would only want to use the principal of the design.IE the 2 drop legs at an angle to offset the forces created by lifting a load.
you could permanently mount a tube the size of the receiver socket to the rt hand or I would mount one on both sides of the receiver mount under the bumper. and if you by chance had a class III or IV receiver hitch your hitch may already be made with a heavy square tube as the torque tube under your bumper. In which case you could possibly create a receiver socket out of that if not just weld a socket to the end of the tube you can buy receiver sockets by them selves in 6, 12, 18and possibly 24" lengths. Once you have that you would need to fabricate the 2 legged drop leg fixture that would also have a receiver stem to plug into the socket. and mount your crane on.
This way the only actual loading you are putting on the truck frame while using the crane would be vertical forces which it is designed for
No mods to the bed the bumper or the frame and any mods done to the receiver would be outboard of its mounting.
For other designed receivers you would merely bolt on a flat plate using the mounting bolts up grading to grade 8 bolts hopefully though. then weld the socket tube to that

ONE note of caution do not under any circumstances drill any holes in the cross tube the receiver is mounted to between the frame mounts. and never cut or weld on the tube anywhere between the side mounts this will void all warrantees and create a safety concern.