318 Duster Rebuild - pros and cons of keeping matching numbers

i'm not one for numbers matching etc, etc, unless the car is something rare (340/4spd, big block, et al) but from my understanding you've already got a serviceable engine and it goes with the car. i'd send that out and have it rebuilt with some minor improvements and updates: a small cam, better pistons & ring pack, good bearings, updated valve guides and seals. things of that nature.

i'd contact @replicaracer43 he's not *that* far from you and intimately knowledgeable about mopar motors. not only that, he's very professional and a stand up dude. he's not going to try and sell you some raced up motor you don't want or need.