i fit a 245 tire, identical setup, and you can easily EASILY fit a 255 and it's still stretching.
265 would be almost stretched even.
considering 245mm is 9.5 inches.. on a 9.5" wheel, and flush is around 10.5" tire (aka 265mm)
my 245's have a LOT of stretch, your 235's would be retarded... 255 still stretches on and easily fits inside the guard.
ED: and 225 front, even without a 5mm spacer, 225 fits perfectly. if you want the same look, go 225 and drop to a 2-3mm spacer.
or at least go hard and do 205 all around or something ridiculous lol.. i've seen 205's on a 10" or 11" rim, it's so stupid and unsafe :P