identify cast or forged

mguner said

It may have a 360 balancer and or converter on it. I was thinking the 318 and 340 cast crank engines balance internally as do the forged. If that is so the converter shouldn't have any large weights on it either. (340 balancer may have designation of "cast crank")

Click to expand...

The 318 cast crank is physically different than the 340 cast crank. The 318 will still be internally balanced the 72-73 340 are external and have a special dampers as you noted that says to "use with cast 340 crank only"

The only way to know what it is, is pull the pan, even then who knows A Balance job would seal the deal.