Dear Welder Series…
I was looking at your universal step notch kit and had some questions before purchase..
Does your universal notch kit fit or has ever been installed on a 1951 Buick Super?
When installing, does the longer side piece go on the inside or outside of the frame? In your pictures I see it on occasions on the inside and on others on the outside. Or maybe on the part of the frame that is boxed?
Is this notch kit the standard size for “most” notch kits or do other widths and lengths exist? Ex. The top of the step span 8 1/2″  or will others span more?

Dear Gabriel…
Gabriel, I don’t know of an installation in a Buick like yours, but this step notch kit (shown below) has been installed in many frames that are similar. i.e. Full frame, larger vehicles.

The longer piece does go on the inside to, in effect, box the inside of the frame.

We do just make this one size.

Thanks for looking at Welder Series parts and for these questions.