Reviving the Dart Lite for daily driving...how should I spend the $$$?

I should clarify to help answers.

Yes, the Dart came as small bolt pattern and 3 speed trans. Build date is in November of 1975, so I think it might be an early bird.

I do have an A body 4 speed OD, with a loose shifter and linkage, and a spare /6 with the /6 bellhousing.

My longer term goals are to check out the spare /6, de-clutter it (truck motor that had lean burn), and assemble the spare /6 with the bellhousing and 4 speed OD and drop them in later.

Right now, I have 500-700 bucks to spend. I am OK with spending all or part, and saving the extra towards the swap goal, but swap will be a little while, so getting the best out of the existing combo would be great.

Driving is mostly local, with a 15-20 minute highway commute in the morning, a 20-30 minute evening commute, and local, around town activites to the store, etc.

I appreciate you reading my version of War and Peace. I enjoy driving the Dart, and ran it daily for 2 years, but couldn't get past the carb issues, and had to park her.