Not only that but the earier snout/pilot is smaller and would wobble around in the back of the newer style crank.
So what you do is have a converter shop cut and put together the pilot/snout side of an new style converter with the internals/splined hub of the old style.
I did this with my brothers 64 dart when I out a 69' slant to his push button 64' trans, even had it cut to high stall, and it only cost me $175