correct front bumper bracket for elastomeric bumper

I need to replace my front bumper brackets for my 71 cuda with a front elastomeric bumper. I heard that these were different than the cars without the elastomeric bumpers. Is this true and if so does anyone have a source for these?

Al

Inner, B, use w/Body Colored Bumper 2962 442-3
Outer, B, use w/Body Colored Bumper 2962 446-7

I think the elastomeric brackets are the same as the chrome except they have the mounting holes elongated for more adjustability.
I know of a '70 Cuda elastomeric bumper mounted with chrome brackets, you'd never know it unless you checked the brackets #s.

Thanks for the info. I will look at my brackets again to see if the holes are elongated. I thought I read somewhere that they were a little longer but the idea of the elongated holes makes sense.