Flywheel dilemma

I have a flywheel that came from a 73 340 which I know has a cast crank and is externally balanced. I want to use this in my son's Duster that will have a 318 which I also know is internally balanced. Will this work without modifications?

If this would not work I have an early 80's 360 that I could give up for him. Would the 73 340 flywheel work on the 360?

Ya know, I searched for a long time for that flywheel for my '73 Cuda. I just plumb gave up. Can't find'em and when I do, some jack *** wants $500 for a thin crack POS.

Went 360 instead!