Rear Window seal's break down

[Pontiac1976]

Sliders there is two main Slider Window's older alloy sliver looking finish 73-80. then the 81-86 black mate finish with two 1/2 openings and 87-91 slider with one opening.
The 81-91 with the small outer lip more of a seal to the glass only fits the slider of this style.
The None slider glass seal of the older two Glass style slider style Seal will work with only the outer style frame that pop out a little over the seal, As 81-91 that slider is more flush fitting will only work with the flush newer style slider.

This all so includes some after market un-less they have a molded in seal as on or two I have seen over the years.

will try find some pic to link to: to show.

[Pontiac1976]

This is a slider that one window opening but 73-80 should work with a None slider this one has the chrome trim.


This is the Alloy two window opening slider style 73-80 that should work with the None slider window none chrome trim.

  This is a side shot of the Slider alloy two openings. See how it stick out from the rubber seal / fits reg. solid glass.

[Pontiac1976]

This is the other one in black.   That will work with a reg. back glass seal too. So there is the up grade to go with chrome package. One with the strip locking chrome inlay, or the black one with/out the strip locking chrome inlay. ( but not the molded in style rubber that one will only work with 81 and up like this pic below. 

 

[Pontiac1976]

The rear Slider looks a lot like top two pic's that factory style standard slider that GM used. This worked with the dual working cab rear window rubber seal for standard glass and the standard slider. But there was two main types slider builds one works and looks a lot like above pic's, other one does Not-Work.
*** The other key is the Rubber Seal has to be Custom style to work with the Standard Slider.***