340 to 360 Harmonic Balancer Swap?

the 340 external balance is not the same as the external balance of the 360's, so no on the dampener, diff stroke/piston weight.
more arm requires...more counter balance...
The flex plate will work but the convertor need to be balanced for the 360, or you must use the external balance 360 convertor.

thank you. that makes sense to me now. If the cranks are interchangeable, it didnt make since to me why the balancer was specific to just the "cast 340 crank" I didnt think about the piston components being different weights..