I have a Griffin in the Tempest. 10 years old. Held up very well. The only issue is self brought on by bent fins from removal. Highly recomended.
In the 1962 Catalina Wagon, I have an Ebay special. Works good too.
http://cgi.ebay.com/ebaymotors/3-ROW...Q5fAccessories
Your 1969 Firebird would be this one, ooh, free shipping.
http://cgi.ebay.com/ebaymotors/1967-...item25649dabc6
HTH,
Dave