Just came across a truck on eBay. Although I'm more knowledgeable about Chevys than I am GMCs, I thought I had seen all of the trim levels for both makes. I thought that "Sierra Grande" was the highest GMC trim level for '75-'80 trucks. I'm guessing that this "Royal Sierra" is a step above that (?). Interesting.
Here's a link to the auction:
http://cgi.ebay.com/ebaymotors/ws/e...9955740&sspagename=ADME:B:SS:US:1123&viewitem=
Here's a link to the auction:
http://cgi.ebay.com/ebaymotors/ws/e...9955740&sspagename=ADME:B:SS:US:1123&viewitem=

Probably was back in '79.