Fleetside Vs Stepside rear bumper

[Myoldtruck]

Im new to C10's so it appears Ive had a learning curve on buying used parts.

Im guessing there is a size difference between a 1970 c10 fleetside chrome rear bumper and a 1970 stepside rear bumper. The width is different im guessing. I bought a complete rear chrome bumper assembly for my fleetside from a craigslist ad. I finally got around to installing the bumper today and found out that it is not wide enough for my truck. So now im stuck with the shorter width bumper for now. Can some someone confirm if there is different widths, so I can relist it for someone else.

I still going to keep the mounting brackets and license plate bracket, so not a total lose.