ordered this for my 2002 seirra. the slot/holes for the screws are a little tight. for fear of breaking the mounting ring i drilled them to the screw size. when assembling, put screws in from the back side, so screw heads are inside door, otherwise the clip nuts hit the door and prevent full insertion of the top lock. then cut off the excess screw length. i ground off all the un-needed mounting lugs.
don't know how it sounds against the stock speaker, it didn't work when i bought the truck, but it sounds great.