I participated in this thread last fall and wanted to provide my insight in installing my own aluminum double step with 7" drop in case it is helpful to others.
I purchased the Carlson-Stromberg 7" drop stamped aluminum steps as their width was the same as the original single steel step. I also prefer the rounded step design as it fits with the curvature of the Airstream. It has been a great mod! For those who had concerns about scraping with a lower step and no lift, I have no lift, and have had NO ISSUES with scraping. It sits higher than the spare, so I used that to judge. Our driveway has a significant grade so I feel I have tested to our satisfaction.
Here is the link to the step model I have (still currently available):
https://factoryrvsurplus.com/collect...t-tape-surface
and here is the link to the outriggers I modified and used to sturdify the installation:
https://www.amazon.com/Trailer-Outri.../dp/B00MJUOUEG
1. After I removed the steps, I modified the outriggers by installing them in reverse (carriage bolt on outside/nut on inside), redrilled holes, and shortened the length of each outrigger. Comment: I had to shear off the extra threads on the nut side of the carraige bolts for the step action to clear--I used red threadlocker when I did the final install (you could spot weld, too)
2. I took plate steel to create "backing plates" to act as a strengthener along the 90 degree channel for the front and back original mounting points. The backing plates sturdified the steps from moving side to side and gave more strength to the mount locations.
3. I swapped the original AS hardware and opted for Grade 8 hardware as I am eternally paranoid. Red thread locker was used on the hardware.
4. Any exposed metal and the flat steel backing plates were appropriately shot with semi-gloss black paint to eliminate any moisture/rust entry points.
Comments: No surrounding plastic or bellypan areas were trimmed or modified in anyway. I also used the
exact same mounting holes on the Airstream--the step and outriggers were instead largified as the steel on these were much more sturdy and of higher gauge than the AS mounting points.
Photos included with descriptions. Our experience has been that these steps are SOLID! You can run up them without any wiggle whatsoever. And, we have found the drain holes are very strategically located so they always stay dry and clean when pulled out, or when folded in.