A couple pros of using clearcoat is it protects the underlying color coat and also makes the motor nice and shiny.
A con is the purists will hate it because it isn’t an original finish.
I’m not sure about the durability of rattle can clear but if if you can spray automotive base/clear you’ll end up with a bullet proof finish on your motor. The clear requires an activator mixed in with it to kick it off instead of air drying like spray can paint does. A bit pricy but worth every penny IMHO.
