I took out the whole floor. It's one piece, or it seemed like it was one piece. It was rotted bad.
I got a 4x8 sheet. It's 48" between the inside wheel wells. I slid it in, measured and cut off the end. There should be enough of the end to make the 4 corners. Once I cut all the pieces I'll lay them in the bed and mark the bolt holes. Then drill, paint and assemble. Later I'll do either a roll in or spray in bedliner. It should last a good long while. It's for hauling stuff not for a car shows.
It's still in the body shop. I hope to have it back this week. I'm taking next week off to finish it off. When I get to the bed floor I'll make sure to take pictures and post it.