For folks needing to sand down a Delrin pivot cup to fit a particular truck, here is a quick tip. Simply wrap the end of a pencil or small wooden dowl with tape to create a snug fit for the pivot cup. Then chuck the end of the pencil into a drill and use that to spin up the cup and hold a piece of sand paper to the outside of the cup. This will allow you to quickly reduce the OD or length to precisely fit the base plate. And to test the fit, just push the baseplate onto the end of the cup with it still attached to the pencil and drill. For even easier use, you can clamp the drill to a bench or in a vise to hold it and allow two-handed access for the sanding and fitting. And make sure your base plate has a small hole drilled in the bottom of the pivot cup hole. That will let air escape when you insert the cup and also enable easy cup extraction with a small punch if you need to pull the cup out for additional adjustments. Finally, realize that the Delrin material does have a bit of give to it, so you have a couple of options for sizing the cup to your particular truck. For example, if your hanger fits loosely in the pivot cup (outside the base plate), then driving the slightly oversized cup into the base plate hole will shrink the inner hole diameter a little bit. Likewise, if the hanger fits just right outside but is too tight with the cup installed, reducing the outer diameter of the cup will eliminate the inner diameter change. If you need to make the cup fit loosely in the base plate, you can always use a flexible adhesive to hold the cup in place.   (66/70)