Float Right Pushes Menu outside of Content Div

I am using Adaptive theme with a set maximum width of 1120px.

When I place the Superfish block menu in either the header or the nav regions and add css float right. In all browsers the horizontal bar appears and there white gap to the right.

I attempted to reduce the amount of menus and add margins but that would negate the purpose of having my menus right aligned with the rest of the page.