I've got a 74 Challenger i'm trying to shave weight on. Its got a 70 front clip, but still has the 74 bumper.

I'VE BEEN TOLD... that the brackets are all the same, and only the bumpers got heavier. Over the years i've also gotten it in my head that there were subtle differences in the 70-72 'small' bumpers. The 70 being the lightest. I KNOW i've seen metal plate behind a 72 bumper, however small.

I dont care if the brackets look stock to Galen Govier, i just want it to look like a 70, and be as light as possible. Do i need 70 only stuff? Just the 70 bumper? What are the specific (even the subtle) differences?

I already have a 70 rear bumper and brackets... so no worries there. Also not interested in fiberglass.