QUOTE 55FirstSeries: "The carb I am considering is a good deal on a reman single barrel YF (2100) that usually fits a GMC 236 engine in this offering." END QUOTE
Someone is pulling your leg !
The Carter type YF number 2100s was produced specifically for replacement of the original Rochester on a Chevrolet 235 CID engine within a certain year range. I have zero, at least to my knowledge, factory Carter information that suggested the use of this unit on a 236 GMC engine. If anyone has such information, I would like a copy for my records.
The 236 used Zenith carburetors as original equipment, and while I really like the type YF, in my opinion, the Zenith is superior.
Jon