Just to add a bit of detail to the Norwood Trim Tag showing a Z28, the “Z” didn’t actually appear until sometime after the second week of April in 70:
http://nastyz28.com/threads/trim-tag....236491/page-3
My 04B car does not have it.
The gas pedal is a strange one for sure. As Ron said, it is thought to be floor mounted for the heel-toe thing, but I have yet to see an official document from GM ever saying so. Even the automatic cars had it.
There are also a few cars out there that seem to be authentic Z’s in every other way that have a hanging pedal. I’m not saying they are as I haven’t seen verified third party corroboration, but the docs seem to support them.
If it was due to racing I find it interesting that the Corvette never picked up on it.