Year specific dampners?

All slant sixes both cast and forged cranks are internally balanced, so you don't have to worry about THAT. From there, it's simply personal preference. For general street performance, I would get something like this.

DODGE PowerBond PB1001N PowerBond Premium OEM Replacement Harmonic Balancers | Summit Racing

If you think that's not enough, there's always this. There are American dealers as well.

Romac Performance Series Harmonic Balancer : Steel/Steel : suit Slant 6 225ci (timing case with spot-welded timing tab)