John,
What code you have on your 1961 6 (235) cylinder pad?
If you have no code on the pad, you most likely have a factory replacement engine or a swapped engine (that has the code ground off).
If the engine is a 1961 engine,
here is information about the engine code. If you want to know the year your engine was cast, the locations of the 235 head date casting code and the block date casting code
code are shown here.
