Fordged 318-3 truck crank or Poly crank, need help ID

4spdcuda66 said
The poly cranks are forged. Look for casting lines. If you don't see any, it's probably a poly unit. Poly cranks are interchangeable with LA cranks.
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Not all of them. There were two generations of poly engines. The 318 poly is the only one that interchanges. It's the second generation poly.