I agree with Doc, there were millions of 9" rears installed in LIGHT duty trucks. They were good for what they were designed for. Heck I broke two with a low compression 400 Ford. I put a Strange S-60 in my Dart, technically it's not a Dana, but is an improved design and can use Dana parts. I went this route because it works for what I'm using it for. If I had a high hp car I go with a 9.5 ring gear set up instead of a 9".