What kind of truck do you have (year and model, some specs would be good)
Short bed, long bed, 4×4 or lifted?
Can you post a picture?
There are a few options you can go with, such as:
1 Build some ramps on top of side rails
2 Build two bars accross the bed with a 90 degree bend on both sides ( this could be round exhaust tubing) weld a bracket at the bottom of both sides, drill some holes, bolt them down to the bed. Do that X2 ( 1 bar for the front and another bar for the rear )
The # 2 option will be the cheapest to build
Just buy the the exhaust piping at any local muffler shop and just have them bend each end 90 degrees
then do the rest at home, if you have a welder, but if you don’t, then bring everything with you to the muffler shop already cut and pre made, so that they can weld the brackets to the ends of the pipes for you, for an extra charge, or extra beer.
Just my 2 cents, we had this set up before, and it worked great.