1964 Dart Owner - In Over My Head

Welcome to the forum , Nice '64 .
These cars are easy to work on , if you have questions just ask here and get answers fast.

BTW as for tires a 235/60x14 or 225/60x15 on 7" win wheels will clear just fine.
Yours look like 8" on the rear.

Air shocks can rub on the gas tank flange coil overs may do the same.

RockAuto has standard repair parts for your car.
Mega Parts USA - Reproduction, NOS and Used Mopar Muscle Car Parts has lock sets with keys for your car.

Have fun with it and consider collector car insurance with agreed value . Of course this means you will need a daily driver.