I didn't think the original Dawn of the Dead was particularly gory. It's mostly a character-driven movie about the people hiding in the mall, while the zombies shamble about in a mindless imitation of everyday life. Parts of it are bloody, but overall, it's much tamer than other zombie flicks. Makes up for it with a good story though.
Dawn of the Dead 1978 is quite gory... You got zombies eating people in the basement, a guy gets his head blown away with a shotgun, a zombie woman that bites a chunck of flesh off a guys shoulder, a zombie gets the top of his head lop with a chopper blade, countless of headshots, a few bikers getting their guts ripped out, the Machete into the zombie's head, a biker gets his arm ripped off from those Blood Pressure Monitors, a few zombies used as target practice... This is from the top of my head.
The story is very gory... It just doesnt seem so bad because the story is very good... :)