I just ordered a pair of these for the rear doors of my 80. Sales tax will vary, but it was $17.05 to my door. Here's a link to the sale and the link to the speakers on the Sony web page. Enjoy!
Sony XS-GTF1627 6.5" 2-Way 190 Watts Car Speakers Pair - Walmart.com
XS-GT1627A | Xplōd™ GT Series Speakers | Sony | Sony Style USA
Sony XS-GTF1627 6.5" 2-Way 190 Watts Car Speakers Pair - Walmart.com
XS-GT1627A | Xplōd™ GT Series Speakers | Sony | Sony Style USA