I totally doubt this has a forged crank, likely a 1 in 10 chance. My car's original, never been apart other than the oil pan 1970 318 has a cast crank. They started making them with cast cranks in 68 or 69.
I thought '70 was the changeover year, but I definitely could be wrong since I don't have anything older than '71. I do know for a fact the 318 in my '71 EL5 Dart GT came with a cast crank in it, the bottom end had never been apart before I started my rebuild and its an all numbers matching deal.
I do know the trucks kept the forged cranks longer than most of the passenger cars did, but I'm not sure why the Challengers would have. I suppose my '72 might have been helpful, but it came to me with a 1983 318 in it (also a cast crank...)
