From the mid 1960's into the late 1970's GM cars had their windshields and rear windows set in a Polysulfide adhesive made by the Thiokol Corporation along with a foam "dam" tape to control the squeeze-out. In the late 1970's GM transitioned to Urethane adhesive due to its superior properties and this video shows you the steps install your glass using Urethane and dam tape. There are more technical tips, downloads and videos at www.rustreplace.com | Belden Speed & Engineering