So welcome to our side of the site. Back in the sixties the big back window was an option and it is less common than the small. Many enthusiasts find the bbw to be more desirable but there are also guys like me who just don't like it. The heaters came in a few different styles too and we have an epic thread about them. It's like 9 pages but it is very good. This is it here...
https://www.67-72chevytrucks.com/vbo...d.php?t=488618.