Different ga barrels on Sav Fox 20ga receiver

I've got a Savage Fox model B series H 20ga double barrel shotgun. Will either the 410ga or 16ga barrels fit my 20ga receiver? I thought it would be nice if I could shoot different gauge barrels on my 20ga receiver. If this is possible, would there have to be any modifications for this to work? Any info will be greatly appreciated. Thanks.