“Max effort daily driver” 318 build vs “Budget” 400 swap

I agree with the comments that the big block swap makes more sense in the context I would be using this car. Hard to argue against more low end torque on a milder build. If built with KB flat tops, I'd have a solid foundation of a short block. And if properly tuned, I expect the fuel economy penalty to be small. I'd port the cast iron heads and run them. I can always bolt on a set of aluminum heads down the road If I chose to. And when someone asks what kind of car I drive, I get to say "I drive a big block Dart!"

I could sell some of my small block stuff to fund schumacher headers. I had considered running HP C body exhaust manifolds, and angle milling the driver's side one to clear the steering shaft. But by then I wouldn't be so far off from having headers shipped to my door. And the tri-y's wouldn't require any machining to fit the car.

Regarding keeping the car running, the car is currently parked. My 7.25 rear started buzzing around december and it's getting replaced by a 29 spline 8.25. I need to take care of that before I can get it on the road again. And I wanted to decide what I was gonna do about the engine before getting that project going, since drivetrain choice would impact driveshaft length as well.