Why do that? Anyway, both the 9004 and the 9007 plug into the same harness connector. Also, both use the same plastic retainer ring to hold it into the lamp housing.
There are notches on the light, and bulb. For you to fit a 9007, or anything other than a 9004 (but still a 9000 series) you would have to grind out those tabs...Also since anythign other than a 9004 has more wattage, your stock wiring might burn up and possibly catch fire because it can't handle the amperage.