Hey Tim - looks like your fingers slipped off of a couple of the keys!
EDIT(I see that you corrected the typos before I hit the "send" key on this message)

In addition to Tim's answer above, he and others answered a similar question on the VCCA site a couple of years ago.
> VCCA discussionHere is my recap of their well documented discussion:
GM offered Running Board Safety Treads for pickups from 1949-1951. Group 8.316, Part #986328. They were listed as an Accessory in the 1949 Chevrolet Truck Restoration Pack. "Items made available at extra cost through the Parts and Accessories Department and installed by the customer or his dealer."
> "Tread" "Running board, safety" This section is not available in the 1950 and 1951 Resto Pacs on the GM and Old Car Manual Project sites.
They are not listed as an accessory in my 1954 Resto Pac. Also not listed in my 1954 RPO Booklet, or my 1954 Cheverolet Accessories Booklet. They are not listed in Group 8.316 of the 1929-1954 Master Parts Catalog.
> 1929-1954 MPC> Picture of an original set (seventh item from the top)> Chevs of the 40's has reproductionsThe running boards are off of my '54 waiting for body work on them then paint. I dread the first time I step on the new paint and scratch it. Not installing running board mats ... yet.