Duster Windshield install Question

Been spending a lot of time reading all the threads about windshield install stuff for the last few weeks and I was hoping to be ready to go tomorrow.
Stumped already....Did a quick test fit of the new weatherstrip. What I'm puzzled about is while the w/strip clearly fits into the "pinch weld" (?) at the top and sides, on the bottom behind the cowl there is nothing that the groove in the weatherstrip fits into other than several small tabs that are bent-up 90 degrees from the body.
Guys talk about using butyl tape inside the w/strip groove, which i planned on doing, but since there's nothing for the groove to set into at the bottom it would be useless there. FSM mentions a filler strip in that location but parts book lists a filler strip only for 2/4 doors or something, not fastbacks and I don't remember removing anything like that.
FSM also says using an adhesive in that area but with all the different tips i read nobody ever mentioned anything like that. Many guys said not to use any butyl or sealer but in that case there would be nothing holding the entire bottom of the windshield to the body except for those 6 or 8 or-so 3/4" inch wide tabs. Make sense what I'm saying? Sorry for the long post