Further research...

vent window seal question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

A little late here but wanted to reaffirm this post. This is one of the single most complaints I hear from customers!

73-80 - 2 Piece Style
81-85 - 2 Piece Style
85-87(91) 1 piece style

The above post is correct in how to identify which 2 piece version you have. The 81-85 has tabs that insert into the division post and fold over, so removing the glassrun on the division bar (where the door glass rolls up) will expose these tabs (81-85) or rivet heads (73-80). There's so little tolerance in these weatherstrips so they can not be interchanged without problems arising.

So it appears that the year of your vehicle doesn't matter on 81-91, you must look to see what you have, as the place you are ordering from probably has it listed wrong.

Of course, where I ordered from lists 81-85 correct, but when you order the full kit, they send you the wrong one. And they don't warn you on 86-91 that they may vary and you need to look, or give you an option.

Further research says the ones from LMC are junk and do not waste your time. They will attempt to have you install the wrong seals, probably made overseas.

 

How to tell the difference.

 

What a pain. I found a pair that were like brandy new from a suburban at u pull it. Shitty I had to bust the side windows with porcelain to get the wing windows but I got them.

 

It's a pain that you have to pull them to find out. Then comes the fun of trying to find a reliable vendor who has the correct one

I also need to tighten up the latches since there is about 1/4" of play which makes it really tough to seal. Last road trip I was on, I ended up folding up cardboard and wedging it in there to cut down on the noise.

But I have to say that I love window vents when the a/c isn't working. It's about the next best thing and helps me survive the summer heat.

 

I also need to tighten up the latches since there is about 1/4" of play which makes it really tough to seal. Last road trip I was on, I ended up folding up cardboard and wedging it in there to cut down on the noise.

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I used the cover from a book of matches a few times...

 

I miss window vents. If they offered them as an option, I'd get them.