NTSC VHS. Clamshell. Theatrical Cut. First time on home video in the US.
From my personal collection.
(Click on the pictures to review them in their native resolution.)
To quote this article
Danny Duchesneau@2022, "Dawn of the Dead VHS issued in the US by distributor Thorn EMI Video in 1983", Dawn of the Dead Collector's Blog, published on 19 February 2022.