340 Identification.

[cudamark]

Pull pan and look at crank. Sharp edges on throws means its a cast crank needing a year correct weird balancer . If it has softer rounded edges, its a forged crank and is internally balanced. Any 273-318-340 forged crank balancer will work on any stock forged crank as they were a neutral balanced motor , everything was balanced to zero so you could mix and match.

For balancing purposes that's mostly true. However there are differences in harmonic balancers in those years. Timing marks and pulley bolt patterns should be taken in consideration too.

 

[pishta]

True. But any neutral (even a neutral balanced V6 damper) will work as designed. Timing marks and symetrical bolt pattern be damned! do you have any more info on the harmonic differences of the internal balanced LA motors or stock neutral balancers?

 

[cudamark]

I've swapped them around without a problem too, but, if you look in the parts manuals, in some applications they had a different part number between the manual transmission and automatic transmission. There must be some difference or Chrysler wouldn't have had a different part for each.