1963 Plymouth Valiant Signet Convertible Restoration...HELLLP!!!

Locate a 67 or newer slant, they changed the crankshaft flange at the converter to a larger bore. That way your trans torque converter will bolt together. If you get a 68 up you need to get a spacer bushing to take up the difference. However the bushing is cheap, so get the best motor you can.