47-55.1 '54 rear bumper on a '53?

[Chopped53]

Hey there. I'm new to the forum. I posted an introduction and photo in the welcome section. I am hoping you guys can help me with this one. My plan is to put a '54 rear bumper on my '53. I like the little license plate bump. I'm thinking of mounting it upside down with the dual exhaust coming out in the bump.

I was in Vegas last week and stopped in at Tuckers Truck Parts to pick up some bed sides and asked about the bumper. They told me that the '54 frame is a different width than the '53 so the rear bumper won't fit, upside down or otherwise.

Is that true? Have any of you managed to get a '54 bumper onto an earlier model truck?

Here's a couple pics to give you an idea of my build.

Appreciate the help!