What do you mean? It is lead. I made an attempt to check the depth of the crack with a thin piece of paper, and it was roughly 1/16" of an inch, I think. 1/8" at the very most, I don't recall. It was obviously hitting something. There was lead at that spot on another 240Z I cut up, roughly the same depth. It's definitely lead, much too soft to be sheet metal.
My floor pans are pretty solid, with only minor rust issues. There was water in my car when I got it, but, a) it was in the back of the passenger side floor, and the car traveled through a pretty serious rain storm to get to my house.
I'd like to have the lead melted out and the area inspected, but that costs money, which I don't have, so for now it stays.
Thanks for the input though. Just to make sure, were you aware that area was a place they used lead (I know I wasn't)? If not, does that change what you just said, knowing that it is lead, and not the sheet metal?