I’ll start the list, it’s a long list so I’ll likely miss a few (or many) things..,
-if 320 is Dynafocal mounts, engine mount most likely OK
-if you have to change to Dynafocal mount, most likely you will also have to change up the gear leg (or legs) too. Best option for nose gear is to upgrade to new style gear leg/mount
-new engine baffles, 360 is a wider engine
-probably new lower cowling, or lots of mods to lower snorkel if carbureted
-probably new throttle & mixture cables needed
-definitely new lower control cable brackets on bottom of panel for prop control
- 90% chance new exhaust needed (rare possibility old exhaust could be modified dependant on old &new engine equipment variables)
-practically everything listed in the FWF kit for the engine/prop combination you chose
-plus the prop & spinner related goodies
Double trouble (effort) if your upgrade choice is a angle valve 360