Learning about the Cast 340

Yes I have the dampner. When I googled the cast # it told me it was from 340 or 318.

Yes 318 are internal balance but that's what my question is about. Did mopar take the internal balance bobweight of the 318 (same crank) toss it in the 340 and add weights to flexplate and dampner to account for heavier pistons. It looks like they did based on this engine I got.