It's just so tempting to mod it.

It's a freaking 1972 dodge dart. Do whatever will make YOU happy.

It's not a rare car. It's not a valuable car. So what are looking for this car to be or looking for it to do? That's the path you need to take.

Me personally I'd be doing wheels, offset hangers, frame connectors, convertor, headers and a 500cfm 2bbl on it. Unless you're going to show it I wouldn't even mess with the engine compartment. To do that right you have to pull down the whole front of the car. The mods I mentioned will allow you to drive the car everyday reliably but also allow you to go further without re-spending money. spend your money once.