1953 Chevy Truck...

What Rochester Carb do I have?

but the engine is a 55-57 block... (the many juries around the net 
are still out on if it is a 235 or 261) 

so... 

on the tag, which I have read is not a part number, but 
an "application tag" it has this: 

7013029

B8 39(the 39 is rotated 90 degrees) 

on the side of the body of the carb: 

Rochester 

GM carburetor

made in the usa

patents appld for

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on the very bottom of the carb, that part that would be mounted to 
the intake... this number appears:

130290 ( I'm pretty sure the 1 is a one, or a REALLY straight scratch)

at the bottom of the carb, but on the side is this number: 

4522 and nearby is the number 37 

and vertically... is the number 036 on the body. 

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The difference between model B carbs is the throttle bore diameter.
216 is 1-1/2"
235 is 1-9/16"
261 is 1-11/16"
mouting bolt spacing on the 216 is about 2-3/4" where as the 235 and 261 are about 3"