Play Super Nes carts on a Super Famicom

[Bayou Billy]

I am thinking about buying a Super Famicom and selling my SNES, i know that i can play the japanese carts on my SNES by breaking the plastic bars on the cartridge slot, but what about the other way around?. Can i play my american carts on the SF by doing something similar, or do i have to buy an adaptor?. Thanks in advance.

[Mayhem]

Adapter only... unless you want to enlarge the cart slot in the plastic shell!