The last set of rails I made for the full size bronco came in at 55lb per side. That's ok for that lumbering beast with a 460CI. weight doesn't matter.
For 77 hp (peak) (on a good day) I chose to go lighter. I used 10 GA ?? tubing, trimmed and welded it to match the stock lower panels
and then set out to mount it. Other owners used the bulkhead bolt and ran chassis stiffeners or added outriggers.
Mine got a thick piece of bar steel that ran the length of the lower door sill ,and just a little wider, welded to the rail then angle iron welded to the underside of it and to the rail. The original sill mounting plates hold the rear of the rail, and the bulkhead bolt went through a piece of c-channel to hold the front.
It looked like it would work, but for a little extra oomph a piece of 1/4" angle iron was welded under the rail and chamfered. If itbreaks,something went really wrong!
before:
after :)
It works!
It wanted to go higher- but started rolling fore and aft thanks to open pumpkins.
I had to jump up and down on the front bumper to flatten the vehicle down after this!