Desert_buick is right, you can't build it too strong, and you're getting real close to too much HP for a 10 bolt if you're planning on driving it hard. I wonder if the 73-76 Torino and the 73 Mustang?cougar might have a 9 inch rear in them.

http://www.fordification.com/rearends-ford01.htm

http://www.drivetraindirect.com/t_gear_calculator.htm

~Jim