1963 Dodge Dart 270 Convertible for the Wife
If you do change it over to a SB, the PB trans are a little different froe each year and the PB setup accordingly.
If the engine was starving for fuel on way home, I wold first pullthe gas tank, and pickup, clean or replace and the fuel filter, and maybe clean the carb.
Its a light car, but slants are basically reliable but not powerhouses. A good running slant with a road gear will keep up with traffic and be cool. The 170 is a short stroke engine and will rev quicker, and the 225 will have more torque. They are still slants.
Very cool car, glad it is a family project.