I need help identifying the correct rear bumper for my truck.

I have an F-150 2000 with step side bed. I tried to locate a bumper on rockauto but the bumper that I thought was correct came and doesn't fit.

Rockauto doesn't list a step side as an option. Are they called anything else? I had a shop call around to salvage yards but there are not any correct bumpers around so I have to order one somewhere and don't want to get the wrong one again.

Thanks for any help.

 

flareside...check LMC truck

 

Supercrew bumpers work as well