It is hard to predict what parts you will need when you are broke down on the road. I have a MAF sensor, an alternator belt, a relay that fits the brake pump, fuel pump and other stuff, a new spark plug and wire, assortment of fuses, wire splices, heat shrink tubing and black tape. And thanks to Dave I have a complete Delco ignition, ICM with coils mounted on it. I saved room for it in the bottom of the box. Dave's got me beat carrying an alternator.
Here is what is inside my toolboxes. I doubt many people carry a fuel pressure tester and a hose to add a can of Freon. 🙂