I also do not understand the value of taking a perfectly good running 413 out and putting a crate motor in only to reinstall the 413 for shows. While the engine blocks interchange just fine, the transmissions are shaped differently and require different mounts. Your existing transmission is a cable shifter, which means you are restricting yourself to a '62 through '65 aluminum body torqueflite. I hope your crate motor is internally balanced, because all those transmissions require it of the engine. Did I mention you'll need to change the length of your drive shaft? In addition, the crate motor wiring is different enough that it's not a question of disconnecting and reconnecting. Your crate motor will likely have a different starter/alternator (assuming that your original engine even has an alternator). It may even have electronic ignition. Then there are the sensors for the gauges and speedometer -- guaranteed different. A modern crate motor vs. a vintage 413 is not a swap, it's an upgrade that's not easily uninstalled.Maybe you need another car for your crate motor and only bring the '59 out for shows.
Happy motoring,
David
'91 K-Imperial driver
'66 Crown Coupe project
'66 LeBaron dual air and every option known to man