All Classified forums require a Site Supporter subscription. It is only $25 per year and you can buy and sell whatever you like on the forum. To become a Site Supporter, go to Your Profile and select "Paid Subscriptions."
I can't confirm right now but if memory serves me that style ended with the 1975 model year
a good guide:http://gmcguy.com/gmc_hubcaps_wheel_covers_and_rims.html
If i can expand upon the topic, is there a trick to making these more secure? i can pull one off by hand. Still seems secure, but is there a trick to make them tighter?