May be the cast cranks are a UK thing? It would be nice to find factory info stating what they put a forged cranks in. The information is cloudy at best.
I did see this in the specs information on the Hamtramck site, 68-72 318's were described as having a cast steel crank. 73 and 74 brochures didn't say. Here's a screen shot of the 72 information. Sorry to spoil the fun.
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