The one piece I have for my '66 is AMD. There is a slight error on the right side at the wheel house, in my opinion, but otherwise it is a really nice piece.
The 1 piece I got for my GTO was a Dynacorn and had a major flaw that made install difficult and the floor didn't look factory at the tail panel. Can't speak for their Chevelle floor, just saying...
I take it the 1 piece is the way to go? just starting the planning and i see there a lot of 3 piece floors too.
The Malibu I bought in October came with the 3 piece, which is really a 7 piece, kit and I installed it so I could have a fuel tank. I have 40 hours in it and it's not close to being done.
I have MAYBE 10 hours in the one piece in the SS...