CW,
The 73 used the bigger block, & IIRC that started with 72 MY when they added the movable passenger seat, & eliminated the "dog bone" shaped loose footrest of 70-71.
PS - for others looking on, it's the same regardless of engine type, as it varied only by MY - 1.7, 1.8 or 2.0L.
.... (except maybe the 72 914-6 ?? - which I'll leave to one of our resident -6-perts).
Tom
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