Yea Phil, that's a forged crank ya got and therefore internally balanced and your vibration dampener is wrong as it belongs to a cast crank. I can't answer your question about the 318 flywheel, sorry. I also read where you found a 187 pan which was good however check to make sure it's got the baffle plate in the bottom and if not I'd highly recommend getting one installed and a milodon windage tray (not mopars tray).
Terry
