Preheat oven to 350 degrees F (175 degrees C). Lightly grease one 9x13 inch pan.
Mix the flour, baking soda, salt, and 1 1/2 cups of the white sugar together. Stir in the beaten eggs and the pineapple with juice and mix well. Pour batter into prepared pan.
Bake at 350 degrees F (175 degrees C) for 30 minutes. Pour Buttery Milk Syrup over top of cake while still warm.
To Make Buttery Milk Syrup: In a sauce pan combine the butter or margarine, evaporated milk, vanilla, and 1/2 cup white sugar. Bring mixture to a boil over medium high heat and cook for about 5 minutes. Pour over cake while still warm.