SB and BB pulley spacing is different... at least with Saginaw pumps. The Saginaw is considered the better pump and is readily available (JY, parts store, new aftermarket). If its not a 100 point resto I'd consider getting a Saginaw pump and matching brackets. Bouchillon can probably fix you up with the brackets. They also offer a pulley spacer kit to provide correct alignment when a SB pump is used on a BB. Its for Saginaw pumps... it may work for Federal.