The Carter came in and it is in about the shape I expected it to be. There definitely is a tag on it that reads "Chevy Truck 53-57". The Carb has a "1895" stamped on the float and "YF4375S" at the base near the throttle body. The throttle body is quite rusted, there seems to be a linkage missin at the bottom to the accelerator pump, and the screw for setting the idle is missing. I'll give the powervalve another shot and if it doesn't cooperate, I'll get on this YF (once I verify that the throttle body fits the manifold.)