If it's the artcore in your profile pic, you'll get soapbars - not dogears - and they'll screw directly into the solid centre block with two long screws. That's why the Soapbars kind of look like they have too many pole-pieces. It's because of mounting screws running through them.
You will have gaps as they're a lot narrower than humbuckers. I don't know if anyone's got a pickup ring that covers those gaps.
More normally, people fit a humbucker sized P90 like this one from Seymour Duncan:
Not quite the same look, but much more convenient. And they mount just like a humbucker. Best option for a humbucker replacement.
Dogears (with the wings) are only for hollowbody guitars. i.e., an acoustic guitar with a pickup fitted like the Gibson ES330, or the Gibson ES175.
