[Bored&Stroked]

I'd ponder the Ford 8" rear with 28 spline axles in your car -- lighter, takes less horsepower, parts availability up the ying-yang and plenty of aftermarket parts (like gears), drum/disc brake options, available all over the place. In the end, it will cost a similar amount to a 9" . . . but a good solid rear end that will take all the flathead horsepower you can throw at it.