Charger IRS in a 69 Dart!!...

Hot Rod power tour came thru here a few weeks ago and one of my favorite cars was a Cuda. '72-3-4 not sure which one, but it had all the late model engine and driveline installed under it and was really well done.
I read somewhere that the ring gear in the late stuff is a 7.5", but will take a considerable beating, 'cause the tolerences and engineering are better.
Good Luck Smooth Dart, Sounds like a fun project, to me!