When I started doing auto glass in the last century I was taught to run a bead of sealant on the gasket in the area between the pinchweld groove and the outer edge of the gasket (do this after putting the rope in the groove). I usually ran a bead about 3/8" dia. This will squash out between the rubber and body, sealing that area. Seal the glass after its in the truck by inserting a plastic or wooden stick between the glass and gasket to make room for a small tip on a caulking tube. The factory manual says to put the seam in the backglass gasket at the top. When you put the gasket on the body you'll probably need to cut the gasket, if you do, cut it 3/16 to a 1/4 long and spring it in. The lock strip starts at the center of the bottom. The backglass normally doesn't need any sealant, but I'd use RTV silicone on the seam if you want to seal it. The 3M sealant won't harden up for a long time, hence you'll smear it every time you touch that area! John
