Jerry, it's your truck - you bought the butt glass for a reason didn't you? If you cut the divider out, save the parts for installation later if you decide to change your mind. Seems like the rubber is going to be pretty much a guessing game, I would go to a glass shop that does custom work and see what they say. I worked at a motor home dealership many moons ago and they had a huge inventory of glass installation rubber profiles. We could fit glass into anything! Good luck.