The "JC" designation was used from 1958 through 1962 and indicated it was a 235 destine for a truck with a "HD Clutch". Depending on the year it could have been installed in a 1/2 through 1-1/2 ton truck.
With a April 1961 casting date it's a pretty safe bet to say it was built and installed in a 1961 model year truck.
Mike B
