Unless it has been changed out it is a 261. O.E. model B Rochester is different internal from 235. If it has a tag on air horn it can be confirmed as to what application it is for.
BC 1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc 1949 GMC 250 project in waiting 1960 C60 pasture art Retired GM dealer tech. 1980 - 2022