My '72 H code Duster didn't have torque boxes installed. I made up a set out of 16 gauge before replacements were commercially available.
Not that I cared. The original engine was long gone before I got the car so "correct" didn't matter. The K frame is a replacement for the bent original so there's no washer there. I could've easily welded one on, but why? The whole idea behind my build was to build a car I like, not a car that's valuable. It's valuable to me and what else matters?