1974 Duster Question - Leave Original?

I'm the 2nd owner of a '74 Duster myself. 48K on the clock. The 318 was an option, but the rust came as standard equipment in Columbus. When I wake up in the morning, she's still a one-option Duster. If the $$'s ever come, I'm going to fix her to be a fun 4-speed car. Since it sounds like the Duster is going to be the easiest to get on the road, I would do that first. If you'd be happier with the Dart as your hot rod, you can sell the Duster and use the $$ on the Dart.