Yes I have successfully installed 5.25" 2-way speakers in the stock location. You will cut sheetmetal, and create new holes for the larger screw pattern. The plastic grill will fit over the larger speakers, presuming that they aren't to deep. Go and take a look at it, just open up the hole a little bit more and that's about it. If you have the stock headunit then I would say go with 4", but if you're looking for more, then definitley go larger.