I have the carb off my 57 235 to replace the gasket between the bowl and throttle plate and was going to use a gasket from a parts carb and noticed the throttle plate has a bore 1/8 larger then the original 235 carb so is my parts carb from a 261,it came off a truck with a manual choke so I might just rebuild that carb.
In this pic you can see how close the 261 power valve vacuum port is to the throat, compared to a 235. Do not focus on the fact that the 261 pic has the port coming out at an angle, that is just because it is a later design.
The one I have looks to be from a 261 as its just as close,now would the bore in a 261 fuel bowl be just as large as the one in the parts carb is the same as the one that came on my 235.
The carb in question most likely is one of those rebuilt carbs with parts from everything,235 fuel bowl with a 261 throttle plate. It came off a 58 235 that had a rod through the block.
