7.25 sure grip

Might be easier, and cheaper to use a Ford 8 inch from an early mustang/comet/ and I think Granada. These have a 5 on 4 1/2 bolt pattern, and will bolt right in to a "A" body, with just a u-joint mod. 7 1/4 mopar rears did have SG's available. However they are few and far between. If you are lucky enough to find a BBP 7 1/4 with a SG it will be a cone type (not a clutch type) and only have two spider gears instead of 4 like the early 7 1/4's. A FYI the BBP axles from a 7 1/4 cannot be installed in the housing that had the SPB axles. For BBP you have to change the complete housing.

PS: I am not trashing the 7 1/4 as I run one in my race car, but it is a weaker rear, and parts are getting hard to find. If you had one, I would say use it, but I would not go out of my way and spend a lot of money to get one.