273 crank in 318 bennifts??

The '64-7 273's have forged cranks.....the '68-9 273's used cast cranks. They will all swap into a 318 (or 340 for that matter) block but remember that the early 273 crank has a small register for the small snout converter those years so if you're running an automatic, you need to have a converter built or conversion parts to change to the later converter. A 318 could have either forged or cast cranks. I usually find the forged ones in trucks and manual transmission vehicles but that's not 100%. If they ran out of one or the other on the assembly line, any engine could have any crank. You should rebalance any time you swap a crank.