The Carter YF design is one of the finest single barrels in existance (my opinion); however they have been used on engines from about 130 to 300 cubic inch displacement. These differ internally as to venturi size. Chances are good that the one you have is probably a replacement unit for a Chevrolet, and is marginally large enough for the 270.
Most of the YF Carters have a STAMPED number followed by the letter "S" on the bowl (center section) of the unit. A common example would be a 967S (Chevy replacement). If you can find this number, we can determine applicability to the 270. None of the raised numbers on the unit have any meaning. The stamped (or recessed) number followed by the letter "S" is the only identification number.
Jon.
