So after inspecting the frame once I got it all unloaded, one of the first things I noticed was that the steel floor panels welded into the footboxes had buckled quite a bit from the welding process and were prone to pop loudly up and down when stepping in and out. I'm sure pretty much everybody's frame is like this. It's not he biggest deal in the world, but I got my frame uncoated so I could easily make modifications as I like.

I'm considering cutting out the welded-in floor panels and replacing them. Without looking closely, I'm guessing the steel used here is 16 or 18-gauge sheet. I'm thinking of using 1/8" thick aluminum and either screwing or riveting it to the frame tubes. Or I could use steel.

Before I choose, I'm curious to know if any of the sanctioning bodies require steel vs aluminum, welded vs fastened, and what kind of thickness. Anybody know or heard of any problems in tech with specific kinds of floor pans?