windshield? you're not "sticking" anything with a windshield because it's captured by the frame, so assume you mean the side window glass? modern tape will no doubt be different to what was around 50 years ago. you might want to talk to whoever you got the tape from on how to use it .... I'd put the smoother side into the channel, you might want to use a rubber mallet gently to insure the glass is seated all the way - the oil trick was to make the seating tape swell, I've not used any oil with modern tape and things sealed fine, if you have enough tape to sacrifice, cut a bit off, oil it, see how it reacts, doubt it'll do anything
Bill
yes I meant the side glass of 51 Chevy 3100. OK just got the oil info from all the tutorials and old Chevy manuals.But I will stick with the experts here as far as getting advise on how and what to use, I'm sure the old timers here are far more knowledgeable than some vendors.