i've got fosgate hpc series fronts and rears 6 3/4" . your infinity's will fit. with slight modification

FRONT- take out plastic speaker bracket on door. just to see if yours fit if not dremel until they do. dynomat , then drill new holes

BACK- a bit trickier, have to take speaker cover and cut out the white dividers on the inside. then set new speaker in bracket
if you get two holes to line up it will work. if not you need to modify the bracket.

its easier than it sounds took me about 3 hours total to figure out/install

with stock grills looks perfect