64 valiant 4 speed conversion questions.

Ok, As I'm still gathering some parts for the conversion, will be doing a 10.5 bellhousing and flywheel since it already has a 727 in it, so the tunnel lip is already modified.

Question is what should I be looking for on the 318 motor to determine what flywheel I will need. I've found a neutral balanced flywheel locally but not sure if that is what i'm going to need.