Don,
I had the same problem last year. Mine is in a 1953 2-ton chevy grain bed. The engine appears to be a 1954 built 261. I ordered two different clutch kits from NAPA and they both turned out to be the 6 bolt. I ended up having my 9 bolt rebuilt by a rebuilder in Fort Worth.
I never did find out the application for the 9 bolt but my other '53 chevy 2-ton winch truck has one too. It has the 53 style 235 in it.
