My new 9 inch assembly showed up the other day. It is a full Strange Engineering unit ordered from Doctor Diff. I went with the Pro nodular iron case with polished gears (3.89 ratio) S trac differential, bigger pinion support, billet 1350 yoke, fabricated housing, boxed mounts for the leaf springs, etc. I have 13 inch Baer brakes to install and then it will be ready to go under the car. This is the third rear end I've bought from Doctor Diff over the years and they always show up ready to go.