Also, thinking about if you have split bench, with no console, your dog could probably go through the center. Takes a little getting used to no arm rests.
This is what I am going to do.
I was able to mount the drivers seat track forward so that you have the seat adjusted most of the way back while driving. I did the opposite with the passenger seat, mounted the tracks as far back as possible. When driving, the passenger will adjust the seat most of the way forward. This allows a nice open area (when the passenger seat is adjusted all the way back) to load the dogs/put stuff in the back.
I made a small 3" wide armrest for each side that also has a cup holder - mounted permanently to my new framework on the base of the seat.
Part of what made me scrap the OEM passenger seat track welded to the new seat idea was the space problem that you referred to. Another problem is the OEM track is so sloppy that the seat rocks on it.
Thanks again for following along. My truck is going to be better on the next trip!