This comes up about once a year. The 273 and 318 used the same crank and rods, with a heavy wrist pin in the 273 to make up for the difference in piston weights. So there are at least two model years of 273s that should have a cast crank although remember MOPAR, never say never!

Also, I cannot imagine a 273 making enough power to put a cast crank in danger, that short stroke and decent sized bearing journals are plenty strong.

R.