http://www.steelerubber.com/search?...cab-pickup#rear-window-gasket-60-0489-81https://www.chevsofthe40s.com/detail/6992/Chevrolet_Glass_Rubber_Back_For_Diecast_Frame.htmlHere are two that I found. The Steele Rubber is where I would go, the windshield seal I got from them was far better quality then the others I purchased from truck parts venders. I would assume the rear glass seal to be the same. With that said, the seal I am using is one of the cheaper ones and it has held up well for the last 13 years on my '37. The seal from Chev's of the '40s does use the metal frame and needs to be drilled for the through screws. Its not a easy job getting them all aligned, drilled and screwed together. Check your outer frame screw holes and make sure they are clean, run a tap down them if need be. The problem I ran into was the screw length, The new seal was thicker so the screws were to short to start, longer screws solved that, but I had to cut each one for a custom length. They need to pull fairly tight yet not bottom out. It will take a few hands to help hold all the pieces while you get them started. Also, don't over tighten them or you will pull the rear frame out of whack creating a wavy frame.
Vulcanized seals are a one piece seal, factory glued together. The other type, you cut and glue yourself.
Joe
