Well I needed a front windshield for my 69 cutlass and i went to ebay again. I found a parts car a little more than an hour from me. 375 dollar was all and i got another rearend and a tail light. Really nice deal. Just look there everyday I guess it only took my 3 months to find what i was looking for I hope your luck can be better than mine.
Any auto glass shop should be able to locate you one. Try sites like Team Chevelle for odd parts, also Year One, Paddock, Sinclairs just to name a few aftermarket suppliers.
For a real good used junkyard selection, try this link.
I got the glass for my 66 chevelle from a local glass dealer out of the yellow pages. I just went down the row, calling each one until I found a few. Then I went to the best deal, which at the time was about $70.00 windshield-no tint or antenna in it! Plus, I got all the installation adheisive and caulk for the install there too.
So, call around first.
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Check out my 1966 Chevelle here: