I don't think so, but I went out and took a picture of my '85 today to check and now I'm not so sure. I'll explain.
The '85 is on top, my '79 is on the bottom. You can see the '85 seat back is about 2-3" below the window. Ever since I bought this truck a few years ago, I've felt the base of the seat made me feel like I was sitting in a hole. I was going to address this this winter when I redo the interior.
I know on my '79 I built up the base of the seat a little, but I don't recall if I also added some spacers at the back of the seat between the base and tracks. I like sitting more vertical. I've done this to several of my vehicles over the years. From the pictures it looks like my '85 seat base sits lower at the back of the seat than the '79 does, which would make the difference you're seeing under the window.
You must be registered for see images attach
You must be registered for see images attach