These are beautiful pieces. So pretty, it seems a shame to hide them under my car where nobody can see them! I may start parking over a mirror. The stubs slide in by hand, then a light tap with a hammer sets them past the internal c-clip. Fit is perfect. They came un-painted; I painted the part of the flange that would be exposed after installation. I swapped the input flange from my original R180 onto the STI diff. Needed a flywheel/gear puller to remove each input flange. The input spline count is the same for both diffs. So, if you change the input flange, the stock driveshaft works. Everything bolted right up, easy as pie. All my old hardware fit and there were NO installation issues. The studs on the diff cover are longer on the STi diff, so it is easier to swap them or remove them and reinstall them once the front diff was seated. I have only driven car around the block and did a few donuts in a parking lot; hope to go to 1/8 mile on Thursday if the weather is good. The first thing I have noticed is that new parts (2004) are better than old parts (1972). My old diff sounded like a box of rocks. The new diff is quiet as a mouse. The car used to power oversteer at a whim, and accellerating out a turn was met with severe wheel spin. Now, the car simply hooks up. More to follow after first trip to the track. Motor is stock, but will be "dropping" stock 2+2 clutch from 5000 rpm. I'm really pleased with the quality of the part and how simple the install was.