Model T Holley Carburetors Model SC and 3 screw

[harvest]

Need some help figuring what year model T carburetors I have here. I dug these out of my storage box last evening and would like to see if some can share some info on these. I looked on the net and couldn't find much on the model SC and this brass 3 screw with the aluminum intake manifold. The SC has a really long intake, could it be for a car? The 3 screw I find little info and could be a rare carburetor?