A factory extractor won't function in an ejector underlug with machining the underlug for the extractor cam, it's not just a matter of swapping parts, you can convert an ejector to not eject tho just be removing a little material as shown in the FAQs, I've done more than a dozen of both ejector to the factory style extractor conversions and conversions from factory extractor to an ejector, both require machining the underlug and drilling for the roll pins to make the conversion.
Tim