I used some RF 8" in the doors. They are deeper than stock. But I removed the magnet covers, then used a heat gun on the inside of the chamber where the speaker sits. Using the gun, I heated the chamber up and while still hot pushed the speakers in to "mold" the shape. I did this several times and the spaeker literally fits like a glove. There were a couple of holes left from the original set so I used some ABS plastic scraps and some adhesive to plug those holes.
2005 GT, Flowmaster, SCT, JLT CAI, Eibach, Baer, FRPP Struts / Dampers, FRPP Deletes, FRPP 4.10's, TA Girdle, BBK UDP's, J&M Upper Link/Lower Control Arms, FRPP GT 500 Front Control Arms, Hurst short throw, Foose / BFG FDW's