I get tape at local SoCal. Measure channel inside, measure glass, subtract, divide by 2. Measure the NEW glass for this calculation. Old glass is 1/4 (.250) thick. New glass from "off shore" is in mm, like 6mm, like .236 thick or less. Most of the time .045 is the correct thickness for my trucks. Some places call it 3/64. I use the rubber black tape, NOT the cork rubber sold by Classic trucks.
Some may not think a lop sided window as bad. If the RTV renders 1/32 (.031) difference, that would be almost zero on one side and .07-.09 on the other of the glass in my era trucks. If that's OK, it's OK. Just pointing out the goodness of tape.
