any tire/wheel advantage to upgrade axles

my demon 83/4 rear end has the small bolt pattern. Is there any advantage to upgrading to the Moser 4.5" axles regarding tires and wheel sizes. How about the brakes??

Yes on all three. Wheels are limited for sbp. All the factory wheels were 13" or 14" and no 15" was available. Much wider brake selection available with bbp.