Several style of running boards have been made over the years.  Some of which are made from fiberglass, plastic, composites, and aluminum.
Don't think they are all alike!
It is important to get as much information about your van as possible in order to get a proper replacement.

We have a huge selection of replacement Running Boards and Ground Effects Kits on our Conversion Parts Center
(CPC) web site.
Click here - www.cpcparts.com