Engine Swap

’m looking for any help or information to swap a 273 engine to a 360 in a 1965 Barracuda with a 4 speed trans. I know the engine mounts must be replaced but they’re not available anymore from Shumacher. And I’m told that I have to replace the flywheel with an externally balanced one. Any help in where I can find one and what else I might run into. I’m buying an ATK 360 engine.
Thanks