All 1960-model slant-6 intakes were aluminum 1bbl items. Some were sandcast, some were semipermanent-mould cast.
The '76 Feather Duster/Dart Lite had an aluminum 1bbl sandcast intake -- totally different from the '60 casting.
In '78, they started using 2-piece electron-beam welded aluminum 1bbl and 2bbl intakes. Super light weight, but prone to crack and casting porosity problems.
In '83, they started using 1-piece sandcast aluminum 1bbl intakes. Similar to the '76 FD/DL casting but not the same. There might have been a 2bbl version of this intake, but if so it is scarce.
Mopar Performance offered a sandcast 1-piece aluminum 2bbl intake, similar to the 1bbl item just above this paragraph but with differences besides the obvious carb mounting pad difference.