Okay. Assuming the correct gasket, the spacer seals the path in the proper gasket. There is not "canal" from the spacer to the throat that allows passage of vacuum to the carb. Am I missing something?

1951 Chevy 3100 5-window
261 cu in, 348 Head, Split Fenton Exhaust
Offy with Dual Weber 2 Bbl Carbs