I bought running boards for my 350, only to realize where the hangers mount on the drivers passenger side is rusted through. I’ve been told I can just have someone cut that piece out and weld a solid steel piece on. My question, is before I look for someone to do this, what is this piece that the hangers mount to called? The pinch weld piece, outer rocker? I just wanna know what to call it and explain before I go calling around. I know this is a common problem, and not a big deal and also probably a relatively common fix... I can tell the previous owner had running boards, and I’m sure removed them when they broke off before he sold the truck. Just don’t wanna take it to an auto body shop and pay crazy prices when I know as long as I find someone who has done this, I can save money. Thanks!

Welcome to the site,,

Being it’s on the inner rocker, I’d call it the inner rocker drop panel.
Like quarter panels etc, ‘drop ‘ usually means the inner sheet metal or fillet panel that ties the outer pinch to the upper floor panels, trunk etc... It would be the rocker panel, inner structure..

Thanks, am I correct to think this is a fairly common problem/fix? Also, do you think I’m crazy to think I could have both sides just replaced and welded w new steel for a few hundred buck?

It might be common in the rust belt areas, here,, No.

Looking at the top image, it looks like the pinch area is gone. I do a lot of panel rust repairs, and the absolute must is, you have to have decent metal remaining to weld to. Mig welding in/on rusted sheet metal doesn’t work well.
As long as surface rust can be removed, and the metal isn’t too thin, a patch can be fabricated and welded into place. If the outer rocker is blistering and starting to rust through, the pinch is questionable, a solid and strong repair would be more difficult.
That said, if the damaged areas are only around the running board bracket mounts, a repair wouldn’t be too hard.
For a few hundred? Just be sure your welder is a compitant welder.
If just ‘making it strong’ is the goal, you may not be too far off. . But if the pinch is blowing out, or worse, making it look good, as well as strong, you may need to fatten the pot some..
I just put a complete floor in a 78 T-Top Trans Am that rotted out. The prior body/welder removed the old floor to fit up the new. It looked like he took it out with a fire axe destroying the inner rockers making my job much more difficult and higher cost to the cars owner.
Certainly shops will give you an estimate, and an idea of what/how to make it work best.
Without inspecting the rockers, hard to say. Just be sure to take it to someone that can do the task, and not be the fire axe guy...