The placement of the adapter bushing on the above photo is 1954-56 intakes. If using a later ECZ-B intake, the carb pad was enlarged and you have to be careful of possible thermostat and/or coolant sensor conversion interference -
Now here is a TED EATON DEDICATED QUESTION -
That adapter looks gnarly to me. I wonder if the 10911 coolant sensor adapter can be modified to fit within the coolant crossover (either welded or preferably machined to thread into the drilled hole)?